Hydrogen-bonding patterns in six derivatives of 2,4-dimethyl­pyrrole

The crystal and mol­ecular structures of 4-ethyl-3,5-dimethyl­pyrrole-2-carbaldehyde, C₁₀H₁₅NO, (I), benzyl 3,5-dimethyl­pyrrole-2-carboxyl­ate, C₁₄H₁₅NO₂, (II), benzyl 4-acetyl-3,5-dimethyl­pyrrole-2-carboxyl­ate, C₁₆H₁₇NO₃, (III), dimethyl 3,5-dimethyl­pyrrole-2,4-dicarboxyl­ate, C₁₀H₁₃NO₄, (IV), 4-ethyl-3,5-dimethyl-2-(p-tos­ylacet­yl)pyrrole, C₁₇H₂₁NO₃S, (V), and ethyl 4-(2-ethoxy­carbonyl-2-hydroxy­acrylo­yl)-3,5-dimethyl­pyrrole-2-carboxyl­ate, C₁₅H₁₉NO₆, (VI), were determined at 130 K. Compounds (I), (II), (IV), (V) and (VI) form hydrogen-bonded dimers [N—H...O=C = 1.97 (2)–2.03 (3) Å]. Four dimers, viz. (I) and (IV)–(VI), have inversion symmetry, while the dimer of (II) has twofold symmetry. Only (III) forms polymeric chains involving hydrogen bonds between the pyrrole H atom and the acetyl carbonyl group [H...O = 1.97 (2) Å] and is further stabilized by CH₃...O inter­actions (C—H...O = 2.28–2.49 Å). Compound (VI) was found to occur as the enol ether in the crystal.

S1. Comment

Pyrroles are both important natural products and crucial starting materials for the synthesis of porphyrins (Gossauer, 1974). Nevertheless, a brief survey of the crystallographic literature shows that few crystal structures of aromatic N-unsubstituted monopyrroles have been reported. Some representative and recent examples are Goddard et al. (1997), Despinoy et al. (1998), Senge et al. (2001), Light et al. (2001), Smith et al. (2001), Paixão et al. (2002), Ramos Silva et al. (2002) and Zhang et al. (2003). In an extension of ongoing studies on the hydrogen-bonding pattern in porphyrins (Senge et al., 1994; Senge & Kalisch, 1999; Senge, 2000) and dipyrromethanes (Senge, 2005), we were interested in the strengths and types of hydrogen bonding of isolated pyrrole units. For initial studies we choose a series of 2,4-dimethylpyrroles with different numbers and types of carbonyl acceptor groups.

The simplest compound is (I), with one potential hydrogen-bond donor and one acceptor group (Fig. 1). As expected, this compound forms strongly hydrogen-bonded dimers, held together by two N—H···O bonds. A similar type of hydrogen bonding with similar geometrical parameters is found for (II) (Fig. 2). Again, hydrogen-bonded dimers are the characteristic feature of the crystal structure. The structure also contains a second, weaker, H···O contact connecting the C31 methyl group with ether atom O2. Although the contact is short and within <2.7 Å as suggested by Steiner (1997) (H31B—O2 = 2.59 Å), the bond angle for this intramolecular contact is rather small (104°). An essentially identical structure of (II) at 150 K has been published by Thompson et al. (2000).

In contrast, compound (III), with carbonyl acceptor groups at both ends of the N–H vector, forms polymeric chains (Fig. 3). The main feature is a classical hydrogen bond involving the pyrrole H atom and the acetyl carbonyl group (N—H1···O3) (Fig. 4). This N—H···O bond is the shortest [1.971 (18) Å] found in the present structures. Carbonyl atom O3 is tightly coordinated by the C51 methyl group (H51C···O3 = 2.49 Å). Likewise, the acetyl methyl group C42 has a short H42C···O1 contact of 2.30 Å. Thus, each pyrrole unit in the polymeric structure in the crystal is held by six hydrogen-bonding interactions as defined by Steiner & Desiraju (1998). Additionally, a short intramolecular contact of 2.28 Å is observed for H31C···O2, involving the ether O atom of the benzyl ester. Note that simple exchange of the benzyl ester for an ethyl ester results in the formation of simple dimers (Paixão et al., 2002 or? 2003).

Compound (IV), despite having two ester groups on two ends of the pyrrole, forms only hydrogen-bonded dimers in the crystal structure (Fig. 5). Like (III), this compound has a short intramolecular contact, H31···O2 (2.31 Å). Pyrrole (V), with a bulkier group in the side chain (tosyl), forms crystals with a molecular arrangement dominated by the formation of standard hydrogen-bonded dimers involving N1—H1···O1 bonding [2.09 (4) Å and 161 (4)°; Fig. 6]. Compound (VI) again forms standard hydrogen-bonded dimers in the crystal structure (Fig. 7). Here, the pyrrole H atom is bonded to the carbonyl group of the 2-ethyl ester group [N1–H1···O1; 2.02 (3) Å and 169 (2)°]. Intriguingly, the butanoic acid side chain does not exist in the keto form (VIa) but rather as the enol ether (VIb). This is clearly evidenced by the longer C41—C42 bond length [1.440 (3) Å] compared with 1.371 (3) Å for C42—C43, differences in the C—O bond lengths [C41—O3 = 1.280 (3) Å and C43—O4 = 1.301 (3) Å] and the unequivocal location of the relevant H atoms. The regiochemistry of the enol ether formation is in line with chemical expectations and the hydroxy group forms an intramolecular hydrogen bond with the neighboring carbonyl group (O4–H4···O3; 1.72 Å and 145°). The six-membered ring system thus formed is almost flat, with an average deviation of the atoms from their least-squares plane by 0.019 (3) Å, and is almost coplanar with the pyrrole ring (the angle between the two planes is 5°). A weak intramolecular methyl (C31) O2 contact was also observed for this compound.

Some of the compounds discussed have served as important building blocks for porphyrins for more than a century (Fischer & Stern, 1940; Omote et al., 1997). They have been investigated for their herbicidal activity (Church et al., 1973 or????1977), used in cyclophane synthesis (Lai et al., 1994) and used as test cases in various physicochemical studies (Abraham et al., 1974; Tabba & Smith, 1984; Thompson et al., 2000).

S2. Experimental

Crystals were handled as described by Hope (1994). The compounds were prepared as described previosly (Küster, 1922; Fischer & Stern, 1940; Hayes et al., 1958; Johnson et al., 1958; Kenner et al., 1977) and crystallized from CH₂Cl₂/n-hexane.

S3. Refinement

H atoms were typically placed in geometrically idealized positions and constrained to ride on their parent atoms with C—H distances in the range of 0.95–0.99 Å, U_iso(H) = 1.2U_eq(C) for CH, OH and CH₂ groups or pyrrole H atoms, and U_iso(H) = 1.5U_eq(C) for methyl groups. The pyrrole H atoms in all structures were refined with isotropic displacement parameters. The H atom at O4 in structure (VIb) was located in difference maps and refined using a standard riding model.

Computing details

For all compounds, data collection: P3 (Siemens, 1995); cell refinement: P3; data reduction: XDISK (Siemens, 1995). Program(s) used to solve structure: SHELXS97 (Sheldrick, 1990) for (1), (2), (3), (4), (6b); SIR92 (Altomare et al., 1994) for (5). For all compounds, program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1995). Software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003) for (1), (2), (6b); SHELXL97 for (3), (4), (5).

Figures

Fig. 1. A view of the dimers formed in (I). Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are shown as dashed lines, and H atoms not involved in the motifs shown have been omitted. Fig. 2. A view of the dimers formed in (II). Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are shown as dashed lines, and H atoms not involved in the motifs shown have been omitted. Fig. 3. A view of (III). Displacement ellipsoids are drawn at the 50% probability level and H atoms have been omitted. Fig. 4. A view of the hydrogen-bonded chains formed in (III) (view down the c axis). Heavy dashed lines indicate classical hydrogen bonds and dashed lines indicate C—H···O interactions. H atoms have been omitted. Fig. 5. A view of the dimers formed in (IV). Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are shown as dashed lines, and H atoms not involved in the motifs shown have been omitted. Fig. 6. A view of the dimers formed in (V). Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are shown as dashed lines, and H atoms not involved in the motifs shown have been omitted. Fig. 7. A view of the dimers formed in (VIb). Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are shown as dashed lines, and H atoms not involved in the motifs shown have been omitted. _publ_section_table_legends

(1) 4-ethyl-3,5-dimethylpyrrole-2-carbaldehyde

Crystal data

C10H15NO	F(000) = 720
Mr = 165.23	Dx = 1.161 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 42 reflections
a = 28.513 (12) Å	θ = 18–24°
b = 9.007 (5) Å	µ = 0.08 mm^−1
c = 7.471 (3) Å	T = 130 K
β = 99.83 (3)°	Block, colorless
V = 1890.5 (15) Å^3	0.55 × 0.41 × 0.40 mm
Z = 8

Data collection

Siemens R3m/V diffractometer	Rint = 0.041
Radiation source: fine-focus sealed tube	θmax = 27.5°, θmin = 2.4°
Graphite monochromator	h = −36→36
ω scans	k = 0→11
2493 measured reflections	l = 0→9
2174 independent reflections	2 standard reflections every 198 reflections
1343 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.064	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.174	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0777P)^2 + 0.1515P] where P = (Fo^2 + 2Fc^2)/3
2174 reflections	(Δ/σ)max < 0.001
117 parameters	Δρmax = 0.26 e Å^−3
0 restraints	Δρmin = −0.32 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.18227 (7)	0.7367 (2)	0.0911 (3)	0.0298 (5)
H1	0.2109 (9)	0.699 (3)	0.058 (3)	0.039 (7)*
C2	0.17296 (7)	0.8866 (3)	0.0997 (3)	0.0276 (5)
C21	0.21027 (8)	0.9912 (3)	0.0790 (3)	0.0300 (5)
C22	0.20186 (9)	1.1542 (3)	0.1030 (4)	0.0361 (6)
H22A	0.2324	1.2069	0.1206	0.054*
H22B	0.1865	1.1691	0.2094	0.054*
H22C	0.1812	1.1927	−0.0054	0.054*
O1	0.24881 (6)	0.94767 (18)	0.0434 (2)	0.0385 (5)
C3	0.12588 (8)	0.9012 (3)	0.1291 (3)	0.0287 (5)
C31	0.09805 (9)	1.0416 (3)	0.1394 (3)	0.0376 (6)
H31A	0.1115	1.0966	0.2494	0.056*
H31B	0.0648	1.0169	0.1433	0.056*
H31C	0.0997	1.1029	0.0323	0.056*
C4	0.10798 (8)	0.7562 (3)	0.1395 (3)	0.0305 (5)
C41	0.05797 (8)	0.7140 (3)	0.1603 (3)	0.0381 (6)
H41A	0.0456	0.7883	0.2379	0.046*
H41B	0.0586	0.6166	0.2221	0.046*
C42	0.02456 (8)	0.7048 (4)	−0.0216 (4)	0.0532 (8)
H42A	0.0232	0.8017	−0.0821	0.080*
H42B	−0.0073	0.6768	−0.0016	0.080*
H42C	0.0364	0.6301	−0.0983	0.080*
C5	0.14365 (8)	0.6567 (3)	0.1157 (3)	0.0311 (5)
C51	0.14405 (9)	0.4907 (3)	0.1144 (4)	0.0386 (6)
H51A	0.1472	0.4553	−0.0070	0.058*
H51B	0.1143	0.4534	0.1463	0.058*
H51C	0.1710	0.4547	0.2031	0.058*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0238 (9)	0.0290 (11)	0.0387 (11)	0.0034 (8)	0.0108 (8)	0.0006 (9)
C2	0.0271 (11)	0.0270 (12)	0.0293 (12)	0.0050 (9)	0.0062 (9)	−0.0008 (10)
C21	0.0283 (11)	0.0314 (12)	0.0312 (12)	0.0020 (10)	0.0074 (9)	0.0001 (10)
C22	0.0387 (13)	0.0303 (13)	0.0410 (14)	−0.0005 (11)	0.0116 (11)	−0.0006 (11)
O1	0.0271 (8)	0.0354 (9)	0.0557 (12)	0.0012 (7)	0.0155 (8)	−0.0056 (8)
C3	0.0260 (11)	0.0341 (13)	0.0275 (12)	0.0045 (9)	0.0087 (9)	0.0011 (10)
C31	0.0335 (12)	0.0397 (15)	0.0412 (14)	0.0097 (11)	0.0108 (11)	−0.0007 (12)
C4	0.0271 (12)	0.0354 (13)	0.0294 (12)	0.0016 (10)	0.0061 (9)	0.0001 (10)
C41	0.0281 (12)	0.0460 (15)	0.0420 (14)	−0.0029 (11)	0.0108 (10)	−0.0014 (12)
C42	0.0303 (13)	0.077 (2)	0.0520 (17)	−0.0088 (14)	0.0075 (12)	−0.0091 (16)
C5	0.0287 (11)	0.0335 (13)	0.0321 (12)	−0.0017 (10)	0.0083 (10)	0.0015 (10)
C51	0.0396 (13)	0.0316 (13)	0.0459 (15)	−0.0006 (11)	0.0109 (11)	−0.0008 (12)

Geometric parameters (Å, º)

N1—C5	1.354 (3)	C31—H31C	0.9800
N1—C2	1.380 (3)	C4—C5	1.390 (3)
N1—H1	0.95 (3)	C4—C41	1.509 (3)
C2—C3	1.403 (3)	C41—C42	1.523 (4)
C2—C21	1.449 (3)	C41—H41A	0.9900
C21—O1	1.238 (3)	C41—H41B	0.9900
C21—C22	1.503 (3)	C42—H42A	0.9800
C22—H22A	0.9800	C42—H42B	0.9800
C22—H22B	0.9800	C42—H42C	0.9800
C22—H22C	0.9800	C5—C51	1.495 (4)
C3—C4	1.410 (3)	C51—H51A	0.9800
C3—C31	1.502 (3)	C51—H51B	0.9800
C31—H31A	0.9800	C51—H51C	0.9800
C31—H31B	0.9800
C5—N1—C2	110.31 (19)	C5—C4—C3	108.1 (2)
C5—N1—H1	126.8 (15)	C5—C4—C41	125.2 (2)
C2—N1—H1	122.5 (16)	C3—C4—C41	126.6 (2)
N1—C2—C3	107.2 (2)	C4—C41—C42	112.3 (2)
N1—C2—C21	118.7 (2)	C4—C41—H41A	109.1
C3—C2—C21	134.0 (2)	C42—C41—H41A	109.1
O1—C21—C2	120.8 (2)	C4—C41—H41B	109.1
O1—C21—C22	120.0 (2)	C42—C41—H41B	109.1
C2—C21—C22	119.2 (2)	H41A—C41—H41B	107.9
C21—C22—H22A	109.5	C41—C42—H42A	109.5
C21—C22—H22B	109.5	C41—C42—H42B	109.5
H22A—C22—H22B	109.5	H42A—C42—H42B	109.5
C21—C22—H22C	109.5	C41—C42—H42C	109.5
H22A—C22—H22C	109.5	H42A—C42—H42C	109.5
H22B—C22—H22C	109.5	H42B—C42—H42C	109.5
C2—C3—C4	106.67 (19)	N1—C5—C4	107.7 (2)
C2—C3—C31	128.0 (2)	N1—C5—C51	121.6 (2)
C4—C3—C31	125.3 (2)	C4—C5—C51	130.7 (2)
C3—C31—H31A	109.5	C5—C51—H51A	109.5
C3—C31—H31B	109.5	C5—C51—H51B	109.5
H31A—C31—H31B	109.5	H51A—C51—H51B	109.5
C3—C31—H31C	109.5	C5—C51—H51C	109.5
H31A—C31—H31C	109.5	H51A—C51—H51C	109.5
H31B—C31—H31C	109.5	H51B—C51—H51C	109.5
C5—N1—C2—C3	−0.7 (3)	C31—C3—C4—C5	177.1 (2)
C5—N1—C2—C21	179.18 (19)	C2—C3—C4—C41	−176.6 (2)
N1—C2—C21—O1	4.3 (3)	C31—C3—C4—C41	0.9 (4)
C3—C2—C21—O1	−175.8 (2)	C5—C4—C41—C42	−89.4 (3)
N1—C2—C21—C22	−175.2 (2)	C3—C4—C41—C42	86.2 (3)
C3—C2—C21—C22	4.7 (4)	C2—N1—C5—C4	0.5 (3)
N1—C2—C3—C4	0.6 (2)	C2—N1—C5—C51	−179.5 (2)
C21—C2—C3—C4	−179.2 (2)	C3—C4—C5—N1	−0.1 (3)
N1—C2—C3—C31	−176.7 (2)	C41—C4—C5—N1	176.2 (2)
C21—C2—C3—C31	3.4 (4)	C3—C4—C5—C51	179.9 (2)
C2—C3—C4—C5	−0.4 (3)	C41—C4—C5—C51	−3.8 (4)

(2) benzyl 3,5-dimethylpyrrole-2-carboxylate

Crystal data

C14H15NO2	F(000) = 976
Mr = 229.27	Dx = 1.252 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 38 reflections
a = 31.793 (18) Å	θ = 19–25°
b = 7.308 (2) Å	µ = 0.08 mm^−1
c = 10.553 (3) Å	T = 130 K
β = 97.02 (3)°	Plate, colorless
V = 2433.5 (17) Å^3	0.50 × 0.50 × 0.08 mm
Z = 8

Data collection

Siemens R3m/V diffractometer	Rint = 0.017
Radiation source: fine-focus sealed tube	θmax = 27.5°, θmin = 2.6°
Graphite monochromator	h = 0→41
ω scans	k = 0→9
3086 measured reflections	l = −13→13
2799 independent reflections	2 standard reflections every 198 reflections
2120 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.144	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0911P)^2 + 0.3712P] where P = (Fo^2 + 2Fc^2)/3
2799 reflections	(Δ/σ)max < 0.001
160 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.28 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.45339 (4)	0.25815 (18)	0.36806 (12)	0.0264 (3)
H1	0.4783 (7)	0.215 (3)	0.359 (2)	0.048 (6)*
C2	0.41943 (4)	0.2605 (2)	0.27300 (14)	0.0245 (3)
C3	0.38441 (4)	0.3285 (2)	0.32611 (15)	0.0261 (3)
C4	0.39866 (5)	0.3667 (2)	0.45403 (15)	0.0298 (4)
H4	0.3819	0.4159	0.5144	0.036*
C5	0.44121 (5)	0.3213 (2)	0.47845 (15)	0.0286 (3)
C21	0.42567 (4)	0.2006 (2)	0.14662 (14)	0.0250 (3)
C22	0.39524 (5)	0.1512 (2)	−0.06526 (14)	0.0299 (3)
H22A	0.4054	0.0232	−0.0660	0.036*
H22B	0.4165	0.2307	−0.0991	0.036*
C23	0.35339 (5)	0.1677 (2)	−0.14755 (14)	0.0275 (3)
C24	0.35349 (5)	0.1689 (2)	−0.27889 (15)	0.0319 (4)
H24	0.3796	0.1623	−0.3137	0.038*
C25	0.31568 (6)	0.1798 (2)	−0.36011 (17)	0.0381 (4)
H25	0.3160	0.1808	−0.4500	0.046*
C26	0.27753 (6)	0.1890 (3)	−0.30964 (19)	0.0450 (5)
H26	0.2516	0.1965	−0.3649	0.054*
C27	0.27717 (5)	0.1873 (3)	−0.17932 (18)	0.0459 (5)
H27	0.2509	0.1932	−0.1450	0.055*
C28	0.31487 (5)	0.1768 (3)	−0.09756 (16)	0.0359 (4)
H28	0.3144	0.1759	−0.0077	0.043*
O1	0.45962 (3)	0.14953 (16)	0.11547 (10)	0.0336 (3)
O2	0.39016 (3)	0.20509 (15)	0.06349 (10)	0.0264 (3)
C31	0.33978 (5)	0.3483 (2)	0.26304 (16)	0.0312 (4)
H31A	0.3267	0.2271	0.2511	0.047*
H31B	0.3399	0.4077	0.1798	0.047*
H31C	0.3235	0.4231	0.3170	0.047*
C51	0.47072 (5)	0.3277 (2)	0.59968 (16)	0.0363 (4)
H51A	0.4798	0.2033	0.6245	0.054*
H51B	0.4562	0.3825	0.6672	0.054*
H51C	0.4956	0.4017	0.5870	0.054*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0173 (6)	0.0307 (7)	0.0312 (7)	−0.0022 (5)	0.0022 (5)	0.0002 (5)
C2	0.0164 (6)	0.0252 (7)	0.0318 (8)	−0.0016 (5)	0.0027 (5)	0.0016 (6)
C3	0.0196 (7)	0.0233 (7)	0.0360 (8)	−0.0014 (5)	0.0057 (6)	0.0014 (6)
C4	0.0255 (7)	0.0296 (8)	0.0355 (8)	−0.0001 (6)	0.0085 (6)	−0.0017 (6)
C5	0.0262 (7)	0.0284 (8)	0.0312 (8)	−0.0056 (6)	0.0040 (6)	0.0002 (6)
C21	0.0173 (6)	0.0250 (7)	0.0324 (8)	−0.0025 (5)	0.0022 (5)	0.0006 (6)
C22	0.0216 (7)	0.0366 (8)	0.0312 (8)	0.0041 (6)	0.0023 (6)	−0.0030 (6)
C23	0.0223 (7)	0.0262 (7)	0.0334 (8)	−0.0011 (6)	0.0005 (6)	0.0005 (6)
C24	0.0285 (8)	0.0316 (8)	0.0349 (8)	0.0012 (6)	0.0018 (6)	−0.0012 (6)
C25	0.0380 (9)	0.0416 (9)	0.0330 (8)	−0.0015 (7)	−0.0033 (7)	0.0001 (7)
C26	0.0280 (8)	0.0573 (12)	0.0465 (10)	−0.0059 (8)	−0.0087 (7)	0.0044 (9)
C27	0.0208 (8)	0.0687 (13)	0.0475 (10)	−0.0055 (8)	0.0009 (7)	0.0067 (9)
C28	0.0239 (7)	0.0494 (10)	0.0343 (9)	−0.0024 (7)	0.0029 (6)	0.0036 (7)
O1	0.0166 (5)	0.0459 (7)	0.0379 (6)	0.0027 (4)	0.0025 (4)	−0.0072 (5)
O2	0.0171 (5)	0.0331 (6)	0.0287 (5)	0.0015 (4)	0.0018 (4)	−0.0005 (4)
C31	0.0194 (7)	0.0324 (8)	0.0419 (9)	0.0031 (6)	0.0048 (6)	0.0000 (7)
C51	0.0346 (8)	0.0412 (9)	0.0322 (8)	−0.0057 (7)	0.0005 (7)	−0.0012 (7)

Geometric parameters (Å, º)

N1—C5	1.353 (2)	C23—C28	1.393 (2)
N1—C2	1.3810 (19)	C24—C25	1.391 (2)
N1—H1	0.87 (2)	C24—H24	0.9500
C2—C3	1.398 (2)	C25—C26	1.385 (3)
C2—C21	1.440 (2)	C25—H25	0.9500
C3—C4	1.399 (2)	C26—C27	1.377 (3)
C3—C31	1.499 (2)	C26—H26	0.9500
C4—C5	1.386 (2)	C27—C28	1.391 (2)
C4—H4	0.9500	C27—H27	0.9500
C5—C51	1.492 (2)	C28—H28	0.9500
C21—O1	1.2244 (18)	C31—H31A	0.9800
C21—O2	1.3430 (18)	C31—H31B	0.9800
C22—O2	1.4426 (18)	C31—H31C	0.9800
C22—C23	1.502 (2)	C51—H51A	0.9800
C22—H22A	0.9900	C51—H51B	0.9800
C22—H22B	0.9900	C51—H51C	0.9800
C23—C24	1.386 (2)
C5—N1—C2	109.92 (13)	C23—C24—H24	119.7
C5—N1—H1	125.7 (14)	C25—C24—H24	119.7
C2—N1—H1	124.3 (14)	C26—C25—C24	119.83 (17)
N1—C2—C3	107.66 (13)	C26—C25—H25	120.1
N1—C2—C21	119.02 (13)	C24—C25—H25	120.1
C3—C2—C21	133.31 (13)	C27—C26—C25	119.90 (16)
C2—C3—C4	106.15 (13)	C27—C26—H26	120.0
C2—C3—C31	127.86 (14)	C25—C26—H26	120.0
C4—C3—C31	125.91 (14)	C26—C27—C28	120.55 (16)
C5—C4—C3	108.97 (14)	C26—C27—H27	119.7
C5—C4—H4	125.5	C28—C27—H27	119.7
C3—C4—H4	125.5	C27—C28—C23	119.91 (16)
N1—C5—C4	107.29 (13)	C27—C28—H28	120.0
N1—C5—C51	122.20 (14)	C23—C28—H28	120.0
C4—C5—C51	130.47 (15)	C21—O2—C22	115.24 (11)
O1—C21—O2	122.04 (14)	C3—C31—H31A	109.5
O1—C21—C2	124.54 (13)	C3—C31—H31B	109.5
O2—C21—C2	113.42 (12)	H31A—C31—H31B	109.5
O2—C22—C23	109.21 (12)	C3—C31—H31C	109.5
O2—C22—H22A	109.8	H31A—C31—H31C	109.5
C23—C22—H22A	109.8	H31B—C31—H31C	109.5
O2—C22—H22B	109.8	C5—C51—H51A	109.5
C23—C22—H22B	109.8	C5—C51—H51B	109.5
H22A—C22—H22B	108.3	H51A—C51—H51B	109.5
C24—C23—C28	119.19 (14)	C5—C51—H51C	109.5
C24—C23—C22	117.93 (14)	H51A—C51—H51C	109.5
C28—C23—C22	122.86 (15)	H51B—C51—H51C	109.5
C23—C24—C25	120.61 (15)
C5—N1—C2—C3	0.11 (17)	C3—C2—C21—O2	−2.7 (2)
C5—N1—C2—C21	179.21 (13)	O2—C22—C23—C24	163.48 (14)
N1—C2—C3—C4	0.30 (16)	O2—C22—C23—C28	−18.3 (2)
C21—C2—C3—C4	−178.62 (15)	C28—C23—C24—C25	0.2 (2)
N1—C2—C3—C31	−176.68 (14)	C22—C23—C24—C25	178.55 (14)
C21—C2—C3—C31	4.4 (3)	C23—C24—C25—C26	−0.2 (3)
C2—C3—C4—C5	−0.60 (17)	C24—C25—C26—C27	−0.1 (3)
C31—C3—C4—C5	176.46 (14)	C25—C26—C27—C28	0.2 (3)
C2—N1—C5—C4	−0.48 (17)	C26—C27—C28—C23	−0.1 (3)
C2—N1—C5—C51	177.49 (14)	C24—C23—C28—C27	−0.1 (3)
C3—C4—C5—N1	0.67 (17)	C22—C23—C28—C27	−178.32 (17)
C3—C4—C5—C51	−177.07 (16)	O1—C21—O2—C22	−1.9 (2)
N1—C2—C21—O1	−1.3 (2)	C2—C21—O2—C22	178.28 (12)
C3—C2—C21—O1	177.48 (16)	C23—C22—O2—C21	−178.51 (12)
N1—C2—C21—O2	178.50 (12)

(3) benzyl 4-acetyl-3,5-dimethylpyrrole-2-carboxylate

Crystal data

C16H17NO3	F(000) = 576
Mr = 271.31	Dx = 1.265 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 44 reflections
a = 13.473 (3) Å	θ = 18–23°
b = 14.359 (3) Å	µ = 0.09 mm^−1
c = 7.489 (2) Å	T = 143 K
β = 100.47 (2)°	Cube, colorless
V = 1424.7 (6) Å^3	0.35 × 0.35 × 0.35 mm
Z = 4

Data collection

Siemens R3m/V diffractometer	Rint = 0.044
Radiation source: fine-focus sealed tube	θmax = 27.5°, θmin = 2.1°
Graphite monochromator	h = −17→17
ω scans	k = −18→0
3519 measured reflections	l = 0→9
3268 independent reflections	2 standard reflections every 198 reflections
2871 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.043	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.120	w = 1/[σ^2(Fo^2) + (0.0692P)^2 + 0.3279P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
3268 reflections	Δρmax = 0.41 e Å^−3
189 parameters	Δρmin = −0.22 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.027 (3)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.55956 (7)	0.46279 (7)	−0.17245 (13)	0.0228 (2)
H1	0.5546 (12)	0.3981 (13)	−0.161 (2)	0.041 (4)*
C2	0.64089 (8)	0.51757 (8)	−0.09509 (15)	0.0230 (2)
C3	0.61709 (8)	0.60974 (8)	−0.13657 (15)	0.0226 (2)
C4	0.51770 (8)	0.60948 (8)	−0.24428 (15)	0.0223 (2)
C5	0.48492 (8)	0.51618 (8)	−0.26261 (15)	0.0217 (2)
C21	0.72660 (8)	0.47072 (8)	0.01540 (16)	0.0241 (2)
C22	0.88392 (9)	0.48559 (9)	0.21436 (18)	0.0299 (3)
H22A	0.9181	0.4374	0.1529	0.036*
H22B	0.8575	0.4561	0.3157	0.036*
C23	0.95594 (9)	0.56237 (9)	0.28383 (16)	0.0275 (3)
C24	1.05350 (9)	0.56252 (10)	0.24823 (18)	0.0325 (3)
H24	1.0753	0.5130	0.1806	0.039*
C25	1.11953 (10)	0.63481 (11)	0.31116 (19)	0.0380 (3)
H25	1.1861	0.6344	0.2860	0.046*
C26	1.08883 (11)	0.70677 (11)	0.4096 (2)	0.0403 (3)
H26	1.1340	0.7561	0.4518	0.048*
C27	0.99164 (11)	0.70709 (10)	0.4470 (2)	0.0418 (3)
H27	0.9703	0.7565	0.5153	0.050*
C28	0.92589 (10)	0.63522 (10)	0.3847 (2)	0.0359 (3)
H28	0.8595	0.6356	0.4109	0.043*
O1	0.72952 (7)	0.38746 (6)	0.04426 (14)	0.0355 (2)
O2	0.80204 (6)	0.52825 (6)	0.08650 (12)	0.0278 (2)
C31	0.68181 (10)	0.69340 (8)	−0.08062 (18)	0.0303 (3)
H31A	0.6463	0.7360	−0.0116	0.045*
H31B	0.6961	0.7252	−0.1890	0.045*
H31C	0.7454	0.6737	−0.0046	0.045*
C41	0.46209 (9)	0.69209 (8)	−0.32033 (16)	0.0249 (3)
C42	0.36115 (9)	0.68132 (9)	−0.44217 (19)	0.0328 (3)
H42A	0.3111	0.6612	−0.3702	0.049*
H42B	0.3660	0.6346	−0.5356	0.049*
H42C	0.3404	0.7411	−0.5002	0.049*
O3	0.49710 (7)	0.77078 (6)	−0.28652 (14)	0.0342 (2)
C51	0.39034 (9)	0.47017 (8)	−0.35905 (17)	0.0259 (3)
H51A	0.3876	0.4739	−0.4905	0.039*
H51B	0.3315	0.5019	−0.3275	0.039*
H51C	0.3901	0.4047	−0.3222	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0228 (5)	0.0149 (5)	0.0305 (5)	0.0004 (3)	0.0041 (4)	−0.0008 (4)
C2	0.0231 (5)	0.0171 (5)	0.0289 (6)	−0.0008 (4)	0.0050 (4)	−0.0007 (4)
C3	0.0238 (5)	0.0170 (5)	0.0273 (5)	−0.0010 (4)	0.0058 (4)	−0.0010 (4)
C4	0.0228 (5)	0.0160 (5)	0.0283 (5)	−0.0001 (4)	0.0054 (4)	−0.0016 (4)
C5	0.0220 (5)	0.0173 (5)	0.0262 (5)	0.0007 (4)	0.0054 (4)	−0.0011 (4)
C21	0.0229 (5)	0.0191 (5)	0.0304 (6)	−0.0003 (4)	0.0052 (4)	−0.0016 (4)
C22	0.0257 (6)	0.0235 (6)	0.0379 (6)	0.0006 (5)	−0.0014 (5)	0.0040 (5)
C23	0.0254 (6)	0.0254 (6)	0.0300 (6)	−0.0009 (4)	0.0003 (4)	0.0035 (5)
C24	0.0270 (6)	0.0366 (7)	0.0328 (6)	−0.0004 (5)	0.0027 (5)	−0.0002 (5)
C25	0.0250 (6)	0.0467 (8)	0.0407 (7)	−0.0081 (6)	0.0013 (5)	0.0045 (6)
C26	0.0373 (7)	0.0348 (7)	0.0441 (8)	−0.0116 (6)	−0.0056 (6)	0.0018 (6)
C27	0.0401 (7)	0.0330 (7)	0.0487 (8)	−0.0008 (6)	−0.0013 (6)	−0.0098 (6)
C28	0.0278 (6)	0.0349 (7)	0.0446 (7)	−0.0012 (5)	0.0053 (5)	−0.0048 (6)
O1	0.0305 (5)	0.0172 (4)	0.0549 (6)	0.0008 (3)	−0.0031 (4)	0.0013 (4)
O2	0.0229 (4)	0.0212 (4)	0.0367 (5)	−0.0019 (3)	−0.0016 (3)	0.0034 (3)
C31	0.0298 (6)	0.0185 (5)	0.0399 (7)	−0.0039 (4)	−0.0006 (5)	0.0001 (5)
C41	0.0259 (5)	0.0177 (5)	0.0316 (6)	0.0015 (4)	0.0068 (4)	0.0002 (4)
C42	0.0287 (6)	0.0196 (6)	0.0465 (7)	0.0014 (4)	−0.0028 (5)	0.0032 (5)
O3	0.0333 (5)	0.0157 (4)	0.0503 (6)	−0.0001 (3)	−0.0007 (4)	−0.0001 (4)
C51	0.0235 (5)	0.0188 (5)	0.0346 (6)	−0.0011 (4)	0.0035 (4)	−0.0014 (4)

Geometric parameters (Å, º)

N1—C5	1.3446 (14)	C24—H24	0.9500
N1—C2	1.3872 (14)	C25—C26	1.376 (2)
N1—H1	0.936 (18)	C25—H25	0.9500
C2—C3	1.3838 (15)	C26—C27	1.388 (2)
C2—C21	1.4573 (16)	C26—H26	0.9500
C3—C4	1.4321 (16)	C27—C28	1.3848 (19)
C3—C31	1.4987 (16)	C27—H27	0.9500
C4—C5	1.4095 (15)	C28—H28	0.9500
C4—C41	1.4622 (15)	C31—H31A	0.9800
C5—C51	1.4992 (15)	C31—H31B	0.9800
C21—O1	1.2143 (15)	C31—H31C	0.9800
C21—O2	1.3425 (14)	C41—O3	1.2328 (15)
C22—O2	1.4578 (14)	C41—C42	1.5017 (17)
C22—C23	1.4982 (17)	C42—H42A	0.9800
C22—H22A	0.9900	C42—H42B	0.9800
C22—H22B	0.9900	C42—H42C	0.9800
C23—C24	1.3879 (17)	C51—H51A	0.9800
C23—C28	1.3925 (19)	C51—H51B	0.9800
C24—C25	1.3923 (19)	C51—H51C	0.9800
C5—N1—C2	110.38 (10)	C24—C25—H25	119.8
C5—N1—H1	123.5 (10)	C25—C26—C27	119.81 (13)
C2—N1—H1	126.0 (10)	C25—C26—H26	120.1
C3—C2—N1	108.38 (10)	C27—C26—H26	120.1
C3—C2—C21	134.14 (11)	C28—C27—C26	119.91 (14)
N1—C2—C21	117.37 (10)	C28—C27—H27	120.0
C2—C3—C4	106.18 (9)	C26—C27—H27	120.0
C2—C3—C31	127.19 (11)	C27—C28—C23	120.76 (13)
C4—C3—C31	126.63 (10)	C27—C28—H28	119.6
C5—C4—C3	107.56 (9)	C23—C28—H28	119.6
C5—C4—C41	127.15 (10)	C21—O2—C22	115.46 (9)
C3—C4—C41	125.29 (10)	C3—C31—H31A	109.5
N1—C5—C4	107.49 (9)	C3—C31—H31B	109.5
N1—C5—C51	118.90 (10)	H31A—C31—H31B	109.5
C4—C5—C51	133.60 (10)	C3—C31—H31C	109.5
O1—C21—O2	122.52 (11)	H31A—C31—H31C	109.5
O1—C21—C2	123.52 (11)	H31B—C31—H31C	109.5
O2—C21—C2	113.94 (10)	O3—C41—C4	120.91 (11)
O2—C22—C23	106.49 (10)	O3—C41—C42	119.32 (10)
O2—C22—H22A	110.4	C4—C41—C42	119.77 (10)
C23—C22—H22A	110.4	C41—C42—H42A	109.5
O2—C22—H22B	110.4	C41—C42—H42B	109.5
C23—C22—H22B	110.4	H42A—C42—H42B	109.5
H22A—C22—H22B	108.6	C41—C42—H42C	109.5
C24—C23—C28	118.81 (12)	H42A—C42—H42C	109.5
C24—C23—C22	120.71 (12)	H42B—C42—H42C	109.5
C28—C23—C22	120.49 (11)	C5—C51—H51A	109.5
C23—C24—C25	120.35 (13)	C5—C51—H51B	109.5
C23—C24—H24	119.8	H51A—C51—H51B	109.5
C25—C24—H24	119.8	C5—C51—H51C	109.5
C26—C25—C24	120.36 (13)	H51A—C51—H51C	109.5
C26—C25—H25	119.8	H51B—C51—H51C	109.5
C5—N1—C2—C3	0.35 (13)	N1—C2—C21—O2	−179.62 (10)
C5—N1—C2—C21	177.07 (10)	O2—C22—C23—C24	−115.76 (13)
N1—C2—C3—C4	−0.45 (13)	O2—C22—C23—C28	63.91 (15)
C21—C2—C3—C4	−176.39 (12)	C28—C23—C24—C25	−0.6 (2)
N1—C2—C3—C31	179.55 (11)	C22—C23—C24—C25	179.11 (12)
C21—C2—C3—C31	3.6 (2)	C23—C24—C25—C26	0.1 (2)
C2—C3—C4—C5	0.39 (13)	C24—C25—C26—C27	0.3 (2)
C31—C3—C4—C5	−179.61 (11)	C25—C26—C27—C28	−0.2 (2)
C2—C3—C4—C41	−179.44 (11)	C26—C27—C28—C23	−0.2 (2)
C31—C3—C4—C41	0.56 (19)	C24—C23—C28—C27	0.6 (2)
C2—N1—C5—C4	−0.09 (12)	C22—C23—C28—C27	−179.06 (13)
C2—N1—C5—C51	179.04 (10)	O1—C21—O2—C22	−5.41 (17)
C3—C4—C5—N1	−0.19 (12)	C2—C21—O2—C22	173.27 (10)
C41—C4—C5—N1	179.64 (11)	C23—C22—O2—C21	−176.90 (10)
C3—C4—C5—C51	−179.14 (12)	C5—C4—C41—O3	176.17 (11)
C41—C4—C5—C51	0.7 (2)	C3—C4—C41—O3	−4.03 (18)
C3—C2—C21—O1	174.71 (13)	C5—C4—C41—C42	−4.16 (18)
N1—C2—C21—O1	−0.95 (17)	C3—C4—C41—C42	175.64 (11)
C3—C2—C21—O2	−3.95 (19)

(4) dimethyl 3,5-dimethylpyrrole-2,4-dicarboxylate

Crystal data

C10H13NO4	F(000) = 448
Mr = 211.21	Dx = 1.363 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 41 reflections
a = 8.150 (4) Å	θ = 20–25°
b = 16.040 (6) Å	µ = 0.11 mm^−1
c = 7.908 (4) Å	T = 130 K
β = 95.31 (3)°	Plate, colorless
V = 1029.3 (8) Å^3	0.40 × 0.38 × 0.10 mm
Z = 4

Data collection

Siemens R3m/V diffractometer	Rint = 0.084
Radiation source: fine-focus sealed tube	θmax = 27.5°, θmin = 2.5°
Graphite monochromator	h = −10→10
ω scans	k = −20→0
2521 measured reflections	l = 0→10
2354 independent reflections	2 standard reflections every 198 reflections
2214 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.047	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.134	w = 1/[σ^2(Fo^2) + (0.0783P)^2 + 0.3875P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max = 0.006
2354 reflections	Δρmax = 0.43 e Å^−3
145 parameters	Δρmin = −0.29 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.046 (7)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.27203 (13)	0.47879 (7)	0.12161 (14)	0.0215 (3)
H1	0.339 (2)	0.5107 (12)	0.069 (2)	0.036 (5)*
C2	0.29355 (15)	0.39398 (7)	0.15179 (15)	0.0213 (3)
C3	0.16107 (15)	0.36563 (8)	0.23399 (15)	0.0217 (3)
C4	0.05807 (15)	0.43659 (8)	0.25194 (15)	0.0217 (3)
C5	0.13218 (15)	0.50579 (8)	0.18147 (15)	0.0211 (3)
C21	0.43822 (15)	0.35482 (8)	0.09224 (16)	0.0226 (3)
C22	0.59889 (19)	0.23282 (9)	0.0807 (2)	0.0337 (3)
H22A	0.5924	0.2327	−0.0437	0.051*
H22B	0.6027	0.1752	0.1224	0.051*
H22C	0.6987	0.2624	0.1260	0.051*
O1	0.53606 (13)	0.39121 (6)	0.01090 (14)	0.0315 (3)
O2	0.45520 (12)	0.27437 (6)	0.13602 (13)	0.0276 (3)
C31	0.12926 (18)	0.27863 (8)	0.29091 (19)	0.0310 (3)
H31A	0.0308	0.2566	0.2254	0.046*
H31B	0.1120	0.2790	0.4119	0.046*
H31C	0.2242	0.2433	0.2727	0.046*
C41	−0.10011 (16)	0.43576 (8)	0.32597 (16)	0.0248 (3)
C42	−0.32876 (18)	0.51776 (11)	0.3875 (2)	0.0376 (4)
H42A	−0.4067	0.4818	0.3196	0.056*
H42B	−0.3676	0.5756	0.3799	0.056*
H42C	−0.3206	0.4996	0.5063	0.056*
O3	−0.16547 (14)	0.37520 (7)	0.38211 (16)	0.0398 (3)
O4	−0.16906 (13)	0.51227 (7)	0.32388 (14)	0.0336 (3)
C51	0.08542 (17)	0.59587 (8)	0.16938 (17)	0.0251 (3)
H51A	0.1635	0.6258	0.1044	0.038*
H51B	0.0880	0.6196	0.2838	0.038*
H51C	−0.0259	0.6012	0.1120	0.038*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0231 (5)	0.0165 (5)	0.0248 (5)	−0.0003 (4)	0.0017 (4)	0.0012 (4)
C2	0.0238 (6)	0.0167 (6)	0.0231 (6)	−0.0010 (4)	−0.0001 (4)	0.0014 (4)
C3	0.0234 (6)	0.0198 (6)	0.0214 (6)	−0.0017 (5)	−0.0009 (4)	0.0009 (4)
C4	0.0221 (6)	0.0214 (6)	0.0213 (6)	−0.0018 (4)	0.0000 (4)	−0.0009 (4)
C5	0.0218 (6)	0.0207 (6)	0.0204 (5)	−0.0007 (4)	−0.0006 (4)	−0.0015 (4)
C21	0.0245 (6)	0.0186 (6)	0.0240 (6)	−0.0002 (5)	−0.0005 (5)	0.0005 (4)
C22	0.0317 (7)	0.0248 (7)	0.0450 (8)	0.0081 (5)	0.0050 (6)	0.0011 (6)
O1	0.0309 (5)	0.0235 (5)	0.0419 (6)	0.0021 (4)	0.0123 (4)	0.0049 (4)
O2	0.0281 (5)	0.0191 (5)	0.0360 (5)	0.0040 (4)	0.0044 (4)	0.0038 (4)
C31	0.0340 (7)	0.0215 (6)	0.0382 (8)	−0.0023 (5)	0.0067 (6)	0.0063 (5)
C41	0.0233 (6)	0.0280 (7)	0.0230 (6)	−0.0030 (5)	0.0011 (5)	−0.0028 (5)
C42	0.0237 (7)	0.0507 (10)	0.0389 (8)	0.0046 (6)	0.0056 (6)	−0.0076 (7)
O3	0.0345 (6)	0.0357 (6)	0.0516 (7)	−0.0073 (5)	0.0162 (5)	0.0032 (5)
O4	0.0271 (5)	0.0338 (6)	0.0411 (6)	0.0037 (4)	0.0105 (4)	−0.0006 (4)
C51	0.0271 (6)	0.0190 (6)	0.0291 (6)	0.0019 (5)	0.0013 (5)	−0.0016 (5)

Geometric parameters (Å, º)

N1—C5	1.3457 (17)	C22—H22B	0.9800
N1—C2	1.3894 (16)	C22—H22C	0.9800
N1—H1	0.88 (2)	C31—H31A	0.9800
C2—C3	1.3875 (18)	C31—H31B	0.9800
C2—C21	1.4523 (18)	C31—H31C	0.9800
C3—C4	1.4291 (18)	C41—O3	1.2117 (18)
C3—C31	1.4963 (18)	C41—O4	1.3492 (17)
C4—C5	1.4034 (18)	C42—O4	1.4408 (18)
C4—C41	1.4644 (19)	C42—H42A	0.9800
C5—C51	1.4951 (18)	C42—H42B	0.9800
C21—O1	1.2188 (17)	C42—H42C	0.9800
C21—O2	1.3398 (16)	C51—H51A	0.9800
C22—O2	1.4498 (18)	C51—H51B	0.9800
C22—H22A	0.9800	C51—H51C	0.9800
C5—N1—C2	110.63 (11)	C21—O2—C22	115.59 (11)
C5—N1—H1	124.2 (13)	C3—C31—H31A	109.5
C2—N1—H1	125.1 (13)	C3—C31—H31B	109.5
C3—C2—N1	108.06 (11)	H31A—C31—H31B	109.5
C3—C2—C21	134.46 (12)	C3—C31—H31C	109.5
N1—C2—C21	117.46 (11)	H31A—C31—H31C	109.5
C2—C3—C4	105.98 (11)	H31B—C31—H31C	109.5
C2—C3—C31	127.63 (12)	O3—C41—O4	122.48 (13)
C4—C3—C31	126.39 (12)	O3—C41—C4	125.94 (13)
C5—C4—C3	108.19 (11)	O4—C41—C4	111.58 (11)
C5—C4—C41	126.38 (12)	O4—C42—H42A	109.5
C3—C4—C41	125.40 (11)	O4—C42—H42B	109.5
N1—C5—C4	107.15 (11)	H42A—C42—H42B	109.5
N1—C5—C51	120.51 (11)	O4—C42—H42C	109.5
C4—C5—C51	132.31 (12)	H42A—C42—H42C	109.5
O1—C21—O2	122.73 (12)	H42B—C42—H42C	109.5
O1—C21—C2	123.67 (12)	C41—O4—C42	116.10 (12)
O2—C21—C2	113.60 (11)	C5—C51—H51A	109.5
O2—C22—H22A	109.5	C5—C51—H51B	109.5
O2—C22—H22B	109.5	H51A—C51—H51B	109.5
H22A—C22—H22B	109.5	C5—C51—H51C	109.5
O2—C22—H22C	109.5	H51A—C51—H51C	109.5
H22A—C22—H22C	109.5	H51B—C51—H51C	109.5
H22B—C22—H22C	109.5
C5—N1—C2—C3	0.24 (14)	C3—C4—C5—C51	−177.41 (13)
C5—N1—C2—C21	179.08 (10)	C41—C4—C5—C51	4.6 (2)
N1—C2—C3—C4	0.19 (13)	C3—C2—C21—O1	174.74 (13)
C21—C2—C3—C4	−178.36 (13)	N1—C2—C21—O1	−3.70 (19)
N1—C2—C3—C31	179.40 (12)	C3—C2—C21—O2	−5.6 (2)
C21—C2—C3—C31	0.8 (2)	N1—C2—C21—O2	175.93 (10)
C2—C3—C4—C5	−0.54 (13)	O1—C21—O2—C22	0.21 (19)
C31—C3—C4—C5	−179.76 (12)	C2—C21—O2—C22	−179.43 (11)
C2—C3—C4—C41	177.51 (11)	C5—C4—C41—O3	177.72 (13)
C31—C3—C4—C41	−1.7 (2)	C3—C4—C41—O3	0.0 (2)
C2—N1—C5—C4	−0.58 (14)	C5—C4—C41—O4	−1.74 (18)
C2—N1—C5—C51	177.79 (11)	C3—C4—C41—O4	−179.43 (11)
C3—C4—C5—N1	0.69 (14)	O3—C41—O4—C42	−1.98 (19)
C41—C4—C5—N1	−177.34 (11)	C4—C41—O4—C42	177.49 (11)

(5) 4-ethyl-3,5-dimethyl-2-[(2-p-tosyl)acetyl]pyrrole

Crystal data

C17H21NO3S	F(000) = 680
Mr = 319.41	Dx = 1.321 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 32 reflections
a = 5.179 (2) Å	θ = 19–23°
b = 13.986 (4) Å	µ = 0.21 mm^−1
c = 22.315 (13) Å	T = 130 K
β = 90.09 (4)°	Block, colorless
V = 1616.4 (12) Å^3	0.30 × 0.25 × 0.25 mm
Z = 4

Data collection

Siemens R3m/V diffractometer	Rint = 0.025
Radiation source: fine-focus sealed tube	θmax = 27.6°, θmin = 1.7°
Graphite monochromator	h = −6→6
ω scans	k = 0→18
4753 measured reflections	l = 0→29
3730 independent reflections	2 standard reflections every 198 reflections
2761 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.123	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0504P)^2 + 0.3777P] where P = (Fo^2 + 2Fc^2)/3
3730 reflections	(Δ/σ)max = 0.003
207 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.35 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	−0.1660 (3)	−0.12872 (13)	0.46468 (8)	0.0227 (4)
H1	−0.162 (5)	−0.080 (2)	0.4896 (12)	0.048 (8)*
C2	−0.0100 (4)	−0.13922 (15)	0.41496 (9)	0.0214 (4)
C3	−0.0735 (4)	−0.22725 (15)	0.38840 (9)	0.0219 (4)
C4	−0.2707 (4)	−0.26807 (15)	0.42328 (9)	0.0234 (4)
C5	−0.3257 (4)	−0.20458 (15)	0.47016 (9)	0.0238 (4)
C21	0.1761 (4)	−0.06612 (15)	0.40306 (9)	0.0222 (4)
C22	0.3212 (4)	−0.06581 (15)	0.34414 (9)	0.0232 (4)
H22A	0.3399	−0.1322	0.3293	0.028*
H22B	0.4961	−0.0390	0.3503	0.028*
C23	0.1875 (4)	0.12431 (15)	0.31164 (9)	0.0224 (4)
C24	0.0052 (4)	0.16606 (16)	0.34897 (10)	0.0275 (5)
H24A	−0.1327	0.1292	0.3648	0.033*
C25	0.0274 (4)	0.26211 (17)	0.36266 (10)	0.0291 (5)
H25A	−0.0958	0.2908	0.3885	0.035*
C26	0.2261 (4)	0.31777 (16)	0.33940 (9)	0.0258 (5)
C27	0.4080 (4)	0.27445 (16)	0.30287 (10)	0.0281 (5)
H27A	0.5464	0.3114	0.2873	0.034*
C28	0.3911 (4)	0.17797 (16)	0.28871 (9)	0.0259 (5)
H28A	0.5169	0.1489	0.2637	0.031*
C29	0.2449 (5)	0.42250 (16)	0.35499 (10)	0.0334 (5)
H29A	0.0742	0.4522	0.3512	0.050*
H29B	0.3658	0.4540	0.3276	0.050*
H29C	0.3068	0.4294	0.3963	0.050*
S1	0.15092 (10)	0.00433 (4)	0.28970 (2)	0.02240 (14)
O1	0.2184 (3)	0.00076 (11)	0.43808 (7)	0.0295 (4)
O2	0.2797 (3)	−0.00856 (11)	0.23319 (6)	0.0291 (4)
O3	−0.1192 (3)	−0.01965 (11)	0.29385 (7)	0.0282 (4)
C31	0.0422 (4)	−0.27299 (16)	0.33353 (9)	0.0274 (5)
H31A	−0.0292	−0.3374	0.3285	0.041*
H31B	0.2301	−0.2771	0.3382	0.041*
H31C	0.0010	−0.2343	0.2982	0.041*
C41	−0.3855 (4)	−0.36645 (15)	0.41722 (10)	0.0289 (5)
H41B	−0.3835	−0.3859	0.3746	0.035*
H41A	−0.5675	−0.3652	0.4307	0.035*
C42	−0.2348 (5)	−0.43920 (17)	0.45433 (11)	0.0359 (6)
H42A	−0.3093	−0.5029	0.4485	0.054*
H42B	−0.2446	−0.4219	0.4968	0.054*
H42C	−0.0539	−0.4395	0.4415	0.054*
C51	−0.5203 (4)	−0.21185 (17)	0.51904 (10)	0.0285 (5)
H51A	−0.5468	−0.1487	0.5370	0.043*
H51B	−0.4581	−0.2564	0.5497	0.043*
H51C	−0.6839	−0.2353	0.5025	0.043*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0244 (9)	0.0205 (9)	0.0232 (9)	−0.0016 (7)	0.0010 (7)	0.0003 (7)
C2	0.0224 (10)	0.0212 (10)	0.0206 (9)	0.0010 (8)	−0.0002 (8)	0.0003 (8)
C3	0.0240 (10)	0.0189 (10)	0.0228 (10)	0.0006 (8)	−0.0025 (8)	0.0012 (8)
C4	0.0254 (11)	0.0208 (11)	0.0239 (10)	−0.0010 (9)	−0.0049 (8)	0.0011 (8)
C5	0.0222 (10)	0.0242 (11)	0.0248 (10)	−0.0031 (9)	−0.0026 (8)	0.0037 (8)
C21	0.0224 (10)	0.0204 (10)	0.0239 (10)	0.0014 (8)	0.0010 (8)	0.0003 (8)
C22	0.0219 (10)	0.0208 (10)	0.0268 (10)	0.0012 (8)	0.0012 (8)	0.0011 (8)
C23	0.0211 (10)	0.0221 (10)	0.0240 (10)	0.0007 (8)	−0.0030 (8)	0.0040 (8)
C24	0.0230 (11)	0.0277 (12)	0.0318 (11)	−0.0024 (9)	0.0047 (9)	0.0018 (9)
C25	0.0281 (12)	0.0292 (12)	0.0299 (11)	0.0018 (9)	0.0019 (9)	−0.0021 (9)
C26	0.0305 (12)	0.0241 (11)	0.0229 (10)	−0.0004 (9)	−0.0043 (9)	0.0055 (8)
C27	0.0279 (11)	0.0292 (12)	0.0273 (11)	−0.0058 (9)	−0.0004 (9)	0.0064 (9)
C28	0.0204 (10)	0.0309 (12)	0.0264 (11)	−0.0008 (9)	0.0022 (8)	0.0031 (9)
C29	0.0448 (14)	0.0260 (12)	0.0295 (11)	−0.0052 (11)	−0.0003 (10)	−0.0002 (9)
S1	0.0211 (3)	0.0243 (3)	0.0218 (2)	−0.0020 (2)	0.00051 (18)	0.0002 (2)
O1	0.0364 (9)	0.0230 (8)	0.0290 (8)	−0.0075 (7)	0.0032 (6)	−0.0053 (6)
O2	0.0306 (8)	0.0338 (9)	0.0230 (7)	−0.0013 (7)	0.0036 (6)	−0.0018 (6)
O3	0.0221 (8)	0.0327 (9)	0.0299 (8)	−0.0036 (6)	−0.0009 (6)	−0.0012 (7)
C31	0.0344 (12)	0.0235 (11)	0.0243 (10)	−0.0020 (9)	0.0003 (9)	−0.0040 (9)
C41	0.0314 (12)	0.0224 (11)	0.0329 (11)	−0.0062 (9)	−0.0051 (9)	0.0001 (9)
C42	0.0405 (14)	0.0245 (12)	0.0427 (14)	−0.0052 (10)	−0.0031 (11)	0.0044 (10)
C51	0.0266 (11)	0.0309 (12)	0.0280 (11)	−0.0050 (9)	0.0026 (9)	0.0019 (9)

Geometric parameters (Å, º)

N1—C5	1.351 (3)	C26—C27	1.386 (3)
N1—C2	1.382 (3)	C26—C29	1.509 (3)
N1—H1	0.88 (3)	C27—C28	1.389 (3)
C2—C3	1.405 (3)	C27—H27A	0.9500
C2—C21	1.430 (3)	C28—H28A	0.9500
C3—C4	1.407 (3)	C29—H29A	0.9800
C3—C31	1.507 (3)	C29—H29B	0.9800
C4—C5	1.402 (3)	C29—H29C	0.9800
C4—C41	1.505 (3)	S1—O2	1.4388 (17)
C5—C51	1.490 (3)	S1—O3	1.4419 (16)
C21—O1	1.238 (2)	C31—H31A	0.9800
C21—C22	1.515 (3)	C31—H31B	0.9800
C22—S1	1.792 (2)	C31—H31C	0.9800
C22—H22A	0.9900	C41—C42	1.526 (3)
C22—H22B	0.9900	C41—H41B	0.9900
C23—C24	1.389 (3)	C41—H41A	0.9900
C23—C28	1.392 (3)	C42—H42A	0.9800
C23—S1	1.758 (2)	C42—H42B	0.9800
C24—C25	1.382 (3)	C42—H42C	0.9800
C24—H24A	0.9500	C51—H51A	0.9800
C25—C26	1.391 (3)	C51—H51B	0.9800
C25—H25A	0.9500	C51—H51C	0.9800
C5—N1—C2	110.37 (18)	C27—C28—C23	119.2 (2)
C5—N1—H1	124.6 (18)	C27—C28—H28A	120.4
C2—N1—H1	125.0 (18)	C23—C28—H28A	120.4
N1—C2—C3	107.17 (18)	C26—C29—H29A	109.5
N1—C2—C21	117.93 (18)	C26—C29—H29B	109.5
C3—C2—C21	134.85 (19)	H29A—C29—H29B	109.5
C2—C3—C4	106.97 (18)	C26—C29—H29C	109.5
C2—C3—C31	128.45 (19)	H29A—C29—H29C	109.5
C4—C3—C31	124.59 (19)	H29B—C29—H29C	109.5
C5—C4—C3	107.73 (19)	O2—S1—O3	118.57 (10)
C5—C4—C41	124.5 (2)	O2—S1—C23	108.28 (10)
C3—C4—C41	127.48 (19)	O3—S1—C23	107.97 (10)
N1—C5—C4	107.76 (18)	O2—S1—C22	107.29 (10)
N1—C5—C51	122.32 (19)	O3—S1—C22	107.79 (10)
C4—C5—C51	129.9 (2)	C23—S1—C22	106.32 (10)
O1—C21—C2	122.78 (19)	C3—C31—H31A	109.5
O1—C21—C22	117.26 (19)	C3—C31—H31B	109.5
C2—C21—C22	119.89 (18)	H31A—C31—H31B	109.5
C21—C22—S1	110.22 (14)	C3—C31—H31C	109.5
C21—C22—H22A	109.6	H31A—C31—H31C	109.5
S1—C22—H22A	109.6	H31B—C31—H31C	109.5
C21—C22—H22B	109.6	C4—C41—C42	111.05 (18)
S1—C22—H22B	109.6	C4—C41—H41B	109.4
H22A—C22—H22B	108.1	C42—C41—H41B	109.4
C24—C23—C28	120.7 (2)	C4—C41—H41A	109.4
C24—C23—S1	119.67 (16)	C42—C41—H41A	109.4
C28—C23—S1	119.57 (17)	H41B—C41—H41A	108.0
C25—C24—C23	119.0 (2)	C41—C42—H42A	109.5
C25—C24—H24A	120.5	C41—C42—H42B	109.5
C23—C24—H24A	120.5	H42A—C42—H42B	109.5
C24—C25—C26	121.5 (2)	C41—C42—H42C	109.5
C24—C25—H25A	119.2	H42A—C42—H42C	109.5
C26—C25—H25A	119.2	H42B—C42—H42C	109.5
C27—C26—C25	118.6 (2)	C5—C51—H51A	109.5
C27—C26—C29	121.1 (2)	C5—C51—H51B	109.5
C25—C26—C29	120.3 (2)	H51A—C51—H51B	109.5
C26—C27—C28	121.1 (2)	C5—C51—H51C	109.5
C26—C27—H27A	119.5	H51A—C51—H51C	109.5
C28—C27—H27A	119.5	H51B—C51—H51C	109.5
C5—N1—C2—C3	−0.8 (2)	C28—C23—C24—C25	0.5 (3)
C5—N1—C2—C21	−178.57 (18)	S1—C23—C24—C25	−175.81 (17)
N1—C2—C3—C4	0.3 (2)	C23—C24—C25—C26	0.7 (3)
C21—C2—C3—C4	177.5 (2)	C24—C25—C26—C27	−1.5 (3)
N1—C2—C3—C31	−179.3 (2)	C24—C25—C26—C29	179.8 (2)
C21—C2—C3—C31	−2.1 (4)	C25—C26—C27—C28	1.1 (3)
C2—C3—C4—C5	0.3 (2)	C29—C26—C27—C28	179.8 (2)
C31—C3—C4—C5	179.9 (2)	C26—C27—C28—C23	0.1 (3)
C2—C3—C4—C41	−173.15 (19)	C24—C23—C28—C27	−0.9 (3)
C31—C3—C4—C41	6.4 (3)	S1—C23—C28—C27	175.41 (16)
C2—N1—C5—C4	1.1 (2)	C24—C23—S1—O2	153.68 (17)
C2—N1—C5—C51	−178.61 (19)	C28—C23—S1—O2	−22.7 (2)
C3—C4—C5—N1	−0.9 (2)	C24—C23—S1—O3	24.1 (2)
C41—C4—C5—N1	172.88 (19)	C28—C23—S1—O3	−152.25 (17)
C3—C4—C5—C51	178.8 (2)	C24—C23—S1—C22	−91.30 (19)
C41—C4—C5—C51	−7.5 (4)	C28—C23—S1—C22	92.31 (18)
N1—C2—C21—O1	6.8 (3)	C21—C22—S1—O2	−172.60 (14)
C3—C2—C21—O1	−170.2 (2)	C21—C22—S1—O3	−43.85 (17)
N1—C2—C21—C22	−170.08 (18)	C21—C22—S1—C23	71.71 (16)
C3—C2—C21—C22	13.0 (4)	C5—C4—C41—C42	−83.9 (3)
O1—C21—C22—S1	−86.0 (2)	C3—C4—C41—C42	88.5 (3)
C2—C21—C22—S1	91.0 (2)

(6b) ethyl 4-(2-ethoxycarbonyl-2-hydroxyacryloyl)-3,5-dimethylpyrrole-2-carboxylate

Crystal data

C15H19NO6	Z = 2
Mr = 309.31	F(000) = 328
Triclinic, P1	Dx = 1.370 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.281 (3) Å	Cell parameters from 25 reflections
b = 10.363 (6) Å	θ = 18–22°
c = 11.003 (7) Å	µ = 0.11 mm^−1
α = 65.11 (5)°	T = 130 K
β = 84.61 (5)°	Parallelepiped, colorless
γ = 86.65 (4)°	0.40 × 0.10 × 0.10 mm
V = 749.6 (8) Å^3

Data collection

Siemens R3m/V diffractometer	Rint = 0.073
Radiation source: fine-focus sealed tube	θmax = 27.5°, θmin = 2.1°
Graphite monochromator	h = 0→9
ω scans	k = −13→13
3686 measured reflections	l = −14→14
3414 independent reflections	2 standard reflections every 198 reflections
2279 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.192	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.1091P)^2 + 0.0847P] where P = (Fo^2 + 2Fc^2)/3
3414 reflections	(Δ/σ)max < 0.001
207 parameters	Δρmax = 0.29 e Å^−3
0 restraints	Δρmin = −0.33 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. The C45, C46 ethyl ester group shows higher thermal libration.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.2582 (2)	0.6334 (2)	0.4331 (2)	0.0307 (4)
H1	0.147 (4)	0.614 (3)	0.475 (3)	0.037*
C2	0.3483 (3)	0.5620 (2)	0.3624 (2)	0.0294 (5)
C3	0.5221 (3)	0.6191 (2)	0.3152 (2)	0.0283 (5)
C4	0.5336 (3)	0.7299 (2)	0.3601 (2)	0.0292 (5)
C5	0.3658 (3)	0.7336 (2)	0.4353 (2)	0.0301 (5)
C21	0.2465 (3)	0.4493 (2)	0.3548 (2)	0.0306 (5)
C22	0.2375 (3)	0.2755 (3)	0.2666 (3)	0.0401 (6)
H22A	0.1506	0.2259	0.3457	0.048*
H22B	0.3244	0.2036	0.2552	0.048*
C23	0.1327 (4)	0.3473 (3)	0.1442 (3)	0.0522 (7)
H23A	0.0762	0.2753	0.1245	0.078*
H23B	0.2172	0.4040	0.0677	0.078*
H23C	0.0361	0.4096	0.1600	0.078*
O1	0.0884 (2)	0.42140 (18)	0.40339 (18)	0.0401 (4)
O2	0.3403 (2)	0.38042 (18)	0.28902 (17)	0.0370 (4)
C31	0.6647 (3)	0.5734 (3)	0.2331 (3)	0.0351 (5)
H31A	0.6211	0.4906	0.2238	0.053*
H31B	0.7801	0.5482	0.2779	0.053*
H31C	0.6863	0.6515	0.1439	0.053*
C41	0.6816 (3)	0.8259 (2)	0.3389 (2)	0.0323 (5)
C42	0.8489 (3)	0.8312 (2)	0.2562 (2)	0.0346 (5)
H42A	0.8691	0.7672	0.2146	0.042*
C43	0.9788 (3)	0.9296 (3)	0.2382 (3)	0.0366 (6)
C44	1.1550 (3)	0.9460 (3)	0.1481 (3)	0.0389 (6)
C45	1.3384 (3)	0.8543 (3)	0.0124 (3)	0.0421 (6)
H45A	1.3486	0.9464	−0.0675	0.050*
H45B	1.4462	0.8421	0.0651	0.050*
C46	1.3335 (4)	0.7383 (4)	−0.0286 (4)	0.0632 (9)
H46A	1.4462	0.7381	−0.0848	0.095*
H46B	1.2258	0.7510	−0.0800	0.095*
H46C	1.3253	0.6476	0.0512	0.095*
O3	0.6631 (2)	0.91189 (19)	0.3956 (2)	0.0462 (5)
O4	0.9632 (3)	1.0192 (2)	0.2933 (2)	0.0509 (5)
H4	0.8670	1.0024	0.3456	0.061*
O5	1.2676 (3)	1.0334 (2)	0.1290 (2)	0.0582 (6)
O6	1.1675 (2)	0.85157 (19)	0.09431 (19)	0.0427 (5)
C51	0.2995 (3)	0.8237 (3)	0.5070 (3)	0.0380 (6)
H51A	0.1755	0.7947	0.5501	0.057*
H51B	0.2955	0.9237	0.4425	0.057*
H51C	0.3838	0.8118	0.5755	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0167 (8)	0.0359 (10)	0.0408 (11)	−0.0055 (7)	0.0071 (7)	−0.0185 (9)
C2	0.0195 (10)	0.0322 (11)	0.0364 (12)	−0.0037 (8)	0.0038 (8)	−0.0150 (10)
C3	0.0171 (9)	0.0306 (11)	0.0349 (11)	−0.0045 (8)	0.0039 (8)	−0.0123 (9)
C4	0.0188 (10)	0.0310 (11)	0.0365 (12)	−0.0058 (8)	0.0050 (8)	−0.0137 (9)
C5	0.0193 (10)	0.0335 (11)	0.0375 (12)	−0.0045 (8)	0.0040 (8)	−0.0158 (10)
C21	0.0211 (10)	0.0329 (11)	0.0369 (12)	−0.0049 (8)	0.0044 (9)	−0.0145 (10)
C22	0.0344 (12)	0.0385 (13)	0.0571 (16)	−0.0135 (10)	0.0080 (11)	−0.0301 (12)
C23	0.0507 (16)	0.0539 (16)	0.0640 (18)	−0.0130 (13)	−0.0024 (14)	−0.0352 (15)
O1	0.0220 (8)	0.0481 (10)	0.0565 (11)	−0.0133 (7)	0.0130 (7)	−0.0298 (9)
O2	0.0240 (8)	0.0426 (9)	0.0537 (10)	−0.0100 (7)	0.0095 (7)	−0.0306 (8)
C31	0.0216 (10)	0.0405 (13)	0.0469 (14)	−0.0066 (9)	0.0093 (9)	−0.0236 (11)
C41	0.0240 (11)	0.0341 (12)	0.0382 (12)	−0.0059 (9)	0.0025 (9)	−0.0147 (10)
C42	0.0211 (10)	0.0354 (12)	0.0446 (13)	−0.0080 (9)	0.0066 (9)	−0.0150 (11)
C43	0.0243 (11)	0.0349 (12)	0.0477 (14)	−0.0064 (9)	0.0022 (10)	−0.0148 (11)
C44	0.0218 (11)	0.0389 (13)	0.0519 (15)	−0.0072 (9)	0.0031 (10)	−0.0153 (12)
C45	0.0218 (11)	0.0458 (14)	0.0477 (15)	−0.0048 (10)	0.0125 (10)	−0.0115 (12)
C46	0.0394 (16)	0.084 (2)	0.070 (2)	−0.0093 (15)	0.0103 (14)	−0.0380 (19)
O3	0.0338 (9)	0.0513 (11)	0.0648 (12)	−0.0177 (8)	0.0154 (8)	−0.0372 (10)
O4	0.0354 (10)	0.0557 (11)	0.0722 (14)	−0.0215 (9)	0.0145 (9)	−0.0383 (11)
O5	0.0311 (10)	0.0567 (12)	0.0900 (16)	−0.0233 (9)	0.0177 (9)	−0.0354 (11)
O6	0.0212 (8)	0.0466 (10)	0.0567 (11)	−0.0110 (7)	0.0143 (7)	−0.0205 (9)
C51	0.0266 (11)	0.0401 (13)	0.0529 (15)	−0.0061 (9)	0.0082 (10)	−0.0264 (12)

Geometric parameters (Å, º)

N1—C5	1.346 (3)	C31—H31C	0.9800
N1—C2	1.383 (3)	C41—O3	1.280 (3)
N1—H1	0.88 (3)	C41—C42	1.440 (3)
C2—C3	1.387 (3)	C42—C43	1.371 (3)
C2—C21	1.456 (3)	C42—H42A	0.9500
C3—C4	1.437 (3)	C43—O4	1.301 (3)
C3—C31	1.498 (3)	C43—C44	1.517 (3)
C4—C5	1.418 (3)	C44—O5	1.197 (3)
C4—C41	1.446 (3)	C44—O6	1.335 (3)
C5—C51	1.491 (3)	C45—C46	1.455 (4)
C21—O1	1.220 (3)	C45—O6	1.461 (3)
C21—O2	1.335 (3)	C45—H45A	0.9900
C22—O2	1.470 (3)	C45—H45B	0.9900
C22—C23	1.494 (4)	C46—H46A	0.9800
C22—H22A	0.9900	C46—H46B	0.9800
C22—H22B	0.9900	C46—H46C	0.9800
C23—H23A	0.9800	O4—H4	0.8400
C23—H23B	0.9800	C51—H51A	0.9800
C23—H23C	0.9800	C51—H51B	0.9800
C31—H31A	0.9800	C51—H51C	0.9800
C31—H31B	0.9800
C5—N1—C2	111.10 (18)	H31A—C31—H31C	109.5
C5—N1—H1	123.5 (17)	H31B—C31—H31C	109.5
C2—N1—H1	125.3 (17)	O3—C41—C42	118.0 (2)
N1—C2—C3	108.47 (19)	O3—C41—C4	118.6 (2)
N1—C2—C21	116.16 (18)	C42—C41—C4	123.5 (2)
C3—C2—C21	135.4 (2)	C43—C42—C41	119.3 (2)
C2—C3—C4	105.81 (19)	C43—C42—H42A	120.4
C2—C3—C31	126.1 (2)	C41—C42—H42A	120.4
C4—C3—C31	128.10 (19)	O4—C43—C42	124.2 (2)
C5—C4—C3	107.88 (18)	O4—C43—C44	113.3 (2)
C5—C4—C41	122.0 (2)	C42—C43—C44	122.5 (2)
C3—C4—C41	130.1 (2)	O5—C44—O6	125.0 (2)
N1—C5—C4	106.7 (2)	O5—C44—C43	123.2 (3)
N1—C5—C51	121.06 (19)	O6—C44—C43	111.8 (2)
C4—C5—C51	132.2 (2)	C46—C45—O6	107.6 (2)
O1—C21—O2	123.2 (2)	C46—C45—H45A	110.2
O1—C21—C2	122.6 (2)	O6—C45—H45A	110.2
O2—C21—C2	114.25 (18)	C46—C45—H45B	110.2
O2—C22—C23	110.3 (2)	O6—C45—H45B	110.2
O2—C22—H22A	109.6	H45A—C45—H45B	108.5
C23—C22—H22A	109.6	C45—C46—H46A	109.5
O2—C22—H22B	109.6	C45—C46—H46B	109.5
C23—C22—H22B	109.6	H46A—C46—H46B	109.5
H22A—C22—H22B	108.1	C45—C46—H46C	109.5
C22—C23—H23A	109.5	H46A—C46—H46C	109.5
C22—C23—H23B	109.5	H46B—C46—H46C	109.5
H23A—C23—H23B	109.5	C43—O4—H4	109.5
C22—C23—H23C	109.5	C44—O6—C45	115.36 (19)
H23A—C23—H23C	109.5	C5—C51—H51A	109.5
H23B—C23—H23C	109.5	C5—C51—H51B	109.5
C21—O2—C22	116.36 (17)	H51A—C51—H51B	109.5
C3—C31—H31A	109.5	C5—C51—H51C	109.5
C3—C31—H31B	109.5	H51A—C51—H51C	109.5
H31A—C31—H31B	109.5	H51B—C51—H51C	109.5
C3—C31—H31C	109.5
C5—N1—C2—C3	−0.6 (3)	C3—C2—C21—O2	1.4 (4)
C5—N1—C2—C21	179.12 (19)	O1—C21—O2—C22	5.4 (3)
N1—C2—C3—C4	−0.3 (2)	C2—C21—O2—C22	−174.0 (2)
C21—C2—C3—C4	−179.9 (2)	C23—C22—O2—C21	83.8 (3)
N1—C2—C3—C31	−179.7 (2)	C5—C4—C41—O3	3.5 (3)
C21—C2—C3—C31	0.7 (4)	C3—C4—C41—O3	−176.4 (2)
C2—C3—C4—C5	1.0 (2)	C5—C4—C41—C42	−175.9 (2)
C31—C3—C4—C5	−179.6 (2)	C3—C4—C41—C42	4.2 (4)
C2—C3—C4—C41	−179.2 (2)	O3—C41—C42—C43	−1.8 (4)
C31—C3—C4—C41	0.2 (4)	C4—C41—C42—C43	177.6 (2)
C2—N1—C5—C4	1.2 (3)	C41—C42—C43—O4	1.2 (4)
C2—N1—C5—C51	−179.3 (2)	C41—C42—C43—C44	−177.5 (2)
C3—C4—C5—N1	−1.3 (3)	O4—C43—C44—O5	−0.6 (4)
C41—C4—C5—N1	178.8 (2)	C42—C43—C44—O5	178.3 (3)
C3—C4—C5—C51	179.2 (2)	O4—C43—C44—O6	179.3 (2)
C41—C4—C5—C51	−0.6 (4)	C42—C43—C44—O6	−1.8 (4)
N1—C2—C21—O1	2.5 (3)	O5—C44—O6—C45	3.4 (4)
C3—C2—C21—O1	−177.9 (3)	C43—C44—O6—C45	−176.5 (2)
N1—C2—C21—O2	−178.18 (19)	C46—C45—O6—C44	175.7 (2)