2-tert-Butyl 4-methyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxyl­ate

Cai, H.-X.; Zhang, Z.-P.

doi:10.1107/S1600536812020120

organic compounds

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Volume 68| Part 6| June 2012| Page o1697

doi:10.1107/S1600536812020120

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2-tert-Butyl 4-methyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxylate

Hong-Xin Cai ^a ^* and Zhao-Po Zhang ^a

^aDepartment of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000, People's Republic of China
^*Correspondence e-mail: me2001@hpu.edu.cn

(Received 8 April 2012; accepted 4 May 2012; online 12 May 2012)

In the title molecule, C₁₃H₁₉NO₄, except for two C atoms of the tert-butyl group, the non-H atoms are almost coplanar (r.m.s. deviation = 0.2542 Å). In the crystal, molecules are linked into centrosymmetric dimers by two intermolecular N—H⋯O hydrogen bonds, forming an R₂²(10) ring motif.

Related literature

For complexes of Schiff bases containing a pyrrole unit, see: Wu et al. (2003 ); Wang et al. (2008 ). For the synthesis of the title compound, see: Sun et al. (2003 ).

Experimental

Crystal data

C₁₃H₁₉NO₄
M_r = 253.29
Monoclinic, P 2₁ /c
a = 11.788 (4) Å
b = 17.045 (6) Å
c = 7.229 (2) Å
β = 106.420 (7)°
V = 1393.2 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.19 × 0.18 × 0.16 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ) T_min = 0.983, T_max = 0.986
7149 measured reflections
2458 independent reflections
1334 reflections with I > 2σ(I)
R_int = 0.050

Refinement

R[F² > 2σ(F²)] = 0.071
wR(F²) = 0.250
S = 1.02
2458 reflections
163 parameters
H-atom parameters constrained
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O4ⁱ	0.86	2.14	2.974 (4)	165
Symmetry code: (i) -x+2, -y, -z+2.

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812020120/vm2170sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812020120/vm2170Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812020120/vm2170Isup3.cml

checkCIF report

Comment top

Schiff bases containing pyrrole units have been extensively investigated due to their excellent coordination abilities (Wu et al., 2003; Wang et al., 2008). As part of our studies on bis(pyrrol-2-yl-methyleneamine) ligands, the crystal structure of the title compound is reported here.

In the title molecule (Fig. 1), except for C12 and C13 atoms of the tert-butyl, the non-hydrogen atoms are almost coplanar (r.m.s. deviation of the non-hydrogen atoms being 0.2542 Å). In the crystal, the molecules are linked into centrosymmetric dimers by two intermolecular N—H···O hydrogen bonds (Table 1), forming a R₂²(10) ring motif (Fig. 2).

Related literature top

For complexes of Schiff bases containing a pyrrole unit, see: Wu et al. (2003); Wang et al. (2008). For the synthesis of the title compound, see: Sun et al. (2003).

Experimental top

The 2-tert-butyl 4-methyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxylate was prepared by a Knorr-type reaction from the condensation of methyl acetoacetate and tert-butyl oximinoacetoacetate according to a literature method (Sun et al., 2003).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure shown with 30% probability displacement ellipsoids.
	Fig. 2. The dimer of the title compounds formed via N—H···O hydrogen bonds shown as the dashed lines. Unlabelled atoms are related with the labelled ones by symmetry operation (-x, 1/2 - y, 1/2 + z).

2-tert-Butyl 4-methyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxylate top

Crystal data top

C₁₃H₁₉NO₄	F(000) = 544
M_r = 253.29	D_x = 1.208 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1135 reflections
a = 11.788 (4) Å	θ = 3.0–21.5°
b = 17.045 (6) Å	µ = 0.09 mm⁻¹
c = 7.229 (2) Å	T = 296 K
β = 106.420 (7)°	Plate, colorless
V = 1393.2 (8) Å³	0.19 × 0.18 × 0.16 mm
Z = 4

Data collection top

Bruker SMART CCD diffractometer	2458 independent reflections
Radiation source: fine-focus sealed tube	1334 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.050
ϕ and ω scans	θ_max = 25.0°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −13→14
T_min = 0.983, T_max = 0.986	k = −19→20
7149 measured reflections	l = −8→7

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.071	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.250	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.1445P)²] where P = (F_o² + 2F_c²)/3
2458 reflections	(Δ/σ)_max < 0.001
163 parameters	Δρ_max = 0.28 e Å⁻³
0 restraints	Δρ_min = −0.21 e Å⁻³

Crystal data top

C₁₃H₁₉NO₄	V = 1393.2 (8) Å³
M_r = 253.29	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 11.788 (4) Å	µ = 0.09 mm⁻¹
b = 17.045 (6) Å	T = 296 K
c = 7.229 (2) Å	0.19 × 0.18 × 0.16 mm
β = 106.420 (7)°

Data collection top

Bruker SMART CCD diffractometer	2458 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2007)	1334 reflections with I > 2σ(I)
T_min = 0.983, T_max = 0.986	R_int = 0.050
7149 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.071	0 restraints
wR(F²) = 0.250	H-atom parameters constrained
S = 1.02	Δρ_max = 0.28 e Å⁻³
2458 reflections	Δρ_min = −0.21 e Å⁻³
163 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
C1	1.1539 (4)	0.4652 (3)	1.0373 (8)	0.1274 (19)
H1B	1.0961	0.5063	1.0193	0.191*
H1C	1.1953	0.4696	0.9409	0.191*
H1D	1.2091	0.4699	1.1630	0.191*
C2	1.1615 (3)	0.3246 (2)	1.0408 (5)	0.0768 (11)
C3	1.0936 (3)	0.25230 (19)	1.0199 (4)	0.0587 (9)
C4	0.9687 (3)	0.24090 (18)	0.9753 (4)	0.0554 (8)
C5	0.9521 (2)	0.16057 (19)	0.9724 (4)	0.0586 (9)
C6	1.1478 (3)	0.1795 (2)	1.0403 (5)	0.0657 (9)
C7	0.8755 (3)	0.30226 (19)	0.9401 (5)	0.0692 (10)
H7A	0.7992	0.2778	0.9138	0.104*
H7B	0.8788	0.3337	0.8315	0.104*
H7C	0.8881	0.3350	1.0521	0.104*
C8	1.2746 (3)	0.1548 (3)	1.0879 (7)	0.0978 (14)
H8A	1.2792	0.0986	1.0897	0.147*
H8B	1.3167	0.1750	1.2123	0.147*
H8C	1.3092	0.1750	0.9923	0.147*
C9	0.8486 (3)	0.1108 (2)	0.9370 (5)	0.0632 (9)
C10	0.6297 (3)	0.1201 (2)	0.8529 (6)	0.0735 (11)
C11	0.6041 (4)	0.0676 (3)	0.6820 (8)	0.131 (2)
H11A	0.6540	0.0222	0.7116	0.197*
H11B	0.6189	0.0952	0.5753	0.197*
H11C	0.5227	0.0517	0.6488	0.197*
C12	0.6181 (4)	0.0814 (3)	1.0336 (7)	0.1063 (15)
H12A	0.6657	0.0348	1.0584	0.159*
H12B	0.5368	0.0677	1.0175	0.159*
H12C	0.6443	0.1169	1.1403	0.159*
C13	0.5522 (3)	0.1940 (3)	0.8125 (8)	0.1084 (16)
H13A	0.5697	0.2261	0.9261	0.163*
H13B	0.4703	0.1790	0.7776	0.163*
H13C	0.5680	0.2229	0.7086	0.163*
O1	1.0949 (2)	0.38906 (15)	1.0199 (4)	0.0925 (9)
O2	1.2657 (3)	0.32986 (18)	1.0728 (6)	0.1295 (13)
O3	0.74888 (17)	0.15373 (14)	0.8891 (3)	0.0713 (8)
O4	0.85058 (19)	0.03974 (15)	0.9488 (4)	0.0876 (9)
N1	1.0615 (2)	0.12471 (17)	1.0127 (4)	0.0674 (8)
H1A	1.0730	0.0748	1.0192	0.081*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.101 (3)	0.078 (3)	0.197 (6)	−0.040 (3)	0.032 (3)	−0.010 (3)
C2	0.053 (2)	0.083 (3)	0.088 (3)	−0.0142 (19)	0.0105 (18)	0.0009 (19)
C3	0.0448 (18)	0.064 (2)	0.066 (2)	−0.0079 (15)	0.0136 (14)	0.0011 (15)
C4	0.0457 (17)	0.063 (2)	0.0539 (18)	−0.0049 (14)	0.0090 (13)	−0.0018 (14)
C5	0.0379 (16)	0.070 (2)	0.064 (2)	−0.0014 (14)	0.0084 (13)	−0.0017 (16)
C6	0.0442 (18)	0.078 (2)	0.074 (2)	−0.0119 (16)	0.0149 (15)	−0.0050 (16)
C7	0.0512 (19)	0.060 (2)	0.091 (2)	0.0005 (16)	0.0119 (17)	0.0041 (17)
C8	0.043 (2)	0.099 (3)	0.146 (4)	0.005 (2)	0.019 (2)	−0.001 (3)
C9	0.0475 (19)	0.058 (2)	0.083 (2)	−0.0048 (15)	0.0169 (16)	−0.0033 (17)
C10	0.0416 (18)	0.074 (2)	0.102 (3)	−0.0111 (16)	0.0146 (17)	−0.009 (2)
C11	0.067 (3)	0.164 (5)	0.141 (4)	−0.010 (3)	−0.005 (3)	−0.062 (4)
C12	0.075 (3)	0.098 (3)	0.152 (4)	−0.020 (2)	0.041 (3)	0.009 (3)
C13	0.050 (2)	0.110 (4)	0.159 (4)	0.008 (2)	0.018 (2)	0.002 (3)
O1	0.0673 (17)	0.0635 (16)	0.145 (3)	−0.0193 (14)	0.0268 (16)	−0.0068 (15)
O2	0.0530 (18)	0.103 (2)	0.215 (4)	−0.0239 (15)	0.0100 (19)	0.007 (2)
O3	0.0359 (12)	0.0687 (15)	0.1046 (19)	−0.0050 (10)	0.0120 (11)	0.0016 (12)
O4	0.0523 (14)	0.0607 (17)	0.144 (2)	−0.0030 (11)	0.0180 (14)	−0.0099 (14)
N1	0.0442 (15)	0.0624 (16)	0.093 (2)	−0.0020 (13)	0.0149 (13)	−0.0030 (14)

Geometric parameters (Å, º) top

C1—O1	1.461 (5)	C8—H8B	0.9600
C1—H1B	0.9600	C8—H8C	0.9600
C1—H1C	0.9600	C9—O4	1.215 (4)
C1—H1D	0.9600	C9—O3	1.344 (4)
C2—O2	1.188 (4)	C10—O3	1.470 (4)
C2—O1	1.334 (4)	C10—C11	1.486 (6)
C2—C3	1.454 (5)	C10—C12	1.504 (6)
C3—C6	1.385 (5)	C10—C13	1.534 (5)
C3—C4	1.429 (4)	C11—H11A	0.9600
C4—C5	1.383 (4)	C11—H11B	0.9600
C4—C7	1.486 (4)	C11—H11C	0.9600
C5—N1	1.382 (4)	C12—H12A	0.9600
C5—C9	1.448 (4)	C12—H12B	0.9600
C6—N1	1.354 (4)	C12—H12C	0.9600
C6—C8	1.496 (5)	C13—H13A	0.9600
C7—H7A	0.9600	C13—H13B	0.9600
C7—H7B	0.9600	C13—H13C	0.9600
C7—H7C	0.9600	N1—H1A	0.8600
C8—H8A	0.9600

O1—C1—H1B	109.5	O4—C9—O3	124.0 (3)
O1—C1—H1C	109.5	O4—C9—C5	125.0 (3)
H1B—C1—H1C	109.5	O3—C9—C5	111.0 (3)
O1—C1—H1D	109.5	O3—C10—C11	110.0 (3)
H1B—C1—H1D	109.5	O3—C10—C12	109.5 (3)
H1C—C1—H1D	109.5	C11—C10—C12	114.2 (4)
O2—C2—O1	120.2 (4)	O3—C10—C13	101.7 (3)
O2—C2—C3	126.4 (4)	C11—C10—C13	111.4 (4)
O1—C2—C3	113.4 (3)	C12—C10—C13	109.3 (3)
C6—C3—C4	108.5 (3)	C10—C11—H11A	109.5
C6—C3—C2	121.7 (3)	C10—C11—H11B	109.5
C4—C3—C2	129.8 (3)	H11A—C11—H11B	109.5
C5—C4—C3	105.7 (3)	C10—C11—H11C	109.5
C5—C4—C7	126.9 (3)	H11A—C11—H11C	109.5
C3—C4—C7	127.4 (3)	H11B—C11—H11C	109.5
N1—C5—C4	108.4 (3)	C10—C12—H12A	109.5
N1—C5—C9	117.9 (3)	C10—C12—H12B	109.5
C4—C5—C9	133.7 (3)	H12A—C12—H12B	109.5
N1—C6—C3	107.3 (3)	C10—C12—H12C	109.5
N1—C6—C8	120.0 (3)	H12A—C12—H12C	109.5
C3—C6—C8	132.6 (3)	H12B—C12—H12C	109.5
C4—C7—H7A	109.5	C10—C13—H13A	109.5
C4—C7—H7B	109.5	C10—C13—H13B	109.5
H7A—C7—H7B	109.5	H13A—C13—H13B	109.5
C4—C7—H7C	109.5	C10—C13—H13C	109.5
H7A—C7—H7C	109.5	H13A—C13—H13C	109.5
H7B—C7—H7C	109.5	H13B—C13—H13C	109.5
C6—C8—H8A	109.5	C2—O1—C1	118.1 (3)
C6—C8—H8B	109.5	C9—O3—C10	123.8 (3)
H8A—C8—H8B	109.5	C6—N1—C5	110.1 (3)
C6—C8—H8C	109.5	C6—N1—H1A	124.9
H8A—C8—H8C	109.5	C5—N1—H1A	124.9
H8B—C8—H8C	109.5

O2—C2—C3—C6	1.3 (6)	N1—C5—C9—O4	3.7 (5)
O1—C2—C3—C6	−178.8 (3)	C4—C5—C9—O4	−176.5 (4)
O2—C2—C3—C4	−177.7 (4)	N1—C5—C9—O3	−176.4 (3)
O1—C2—C3—C4	2.2 (5)	C4—C5—C9—O3	3.4 (5)
C6—C3—C4—C5	0.6 (4)	O2—C2—O1—C1	0.1 (6)
C2—C3—C4—C5	179.7 (3)	C3—C2—O1—C1	−179.8 (3)
C6—C3—C4—C7	−179.6 (3)	O4—C9—O3—C10	2.7 (5)
C2—C3—C4—C7	−0.6 (6)	C5—C9—O3—C10	−177.2 (3)
C3—C4—C5—N1	−0.2 (3)	C11—C10—O3—C9	−63.7 (5)
C7—C4—C5—N1	−179.9 (3)	C12—C10—O3—C9	62.6 (4)
C3—C4—C5—C9	180.0 (3)	C13—C10—O3—C9	178.1 (3)
C7—C4—C5—C9	0.2 (6)	C3—C6—N1—C5	0.7 (4)
C4—C3—C6—N1	−0.8 (4)	C8—C6—N1—C5	179.4 (3)
C2—C3—C6—N1	−180.0 (3)	C4—C5—N1—C6	−0.4 (4)
C4—C3—C6—C8	−179.3 (4)	C9—C5—N1—C6	179.5 (3)
C2—C3—C6—C8	1.5 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O4ⁱ	0.86	2.14	2.974 (4)	165

Symmetry code: (i) −x+2, −y, −z+2.

Experimental details

Crystal data
Chemical formula	C₁₃H₁₉NO₄
M_r	253.29
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	11.788 (4), 17.045 (6), 7.229 (2)
β (°)	106.420 (7)
V (Å³)	1393.2 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.19 × 0.18 × 0.16

Data collection
Diffractometer	Bruker SMART CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2007)
T_min, T_max	0.983, 0.986
No. of measured, independent and observed [I > 2σ(I)] reflections	7149, 2458, 1334
R_int	0.050
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.071, 0.250, 1.02
No. of reflections	2458
No. of parameters	163
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.28, −0.21

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O4ⁱ	0.86	2.14	2.974 (4)	164.8

Symmetry code: (i) −x+2, −y, −z+2.

Acknowledgements

The authors are grateful for financial support from the Doctoral Foundation of Henan Polytechnic University (grant No. B2009-70 648364).

References

Bruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sun, L., et al. (2003). J. Med. Chem. 46, 1116–1119. Web of Science CrossRef PubMed CAS Google Scholar
Wang, Y., Yang, Z.-Y. & Chen, Z.-N. (2008). Bioorg. Med. Chem. Lett. 18, 298–303. Web of Science CSD CrossRef PubMed CAS Google Scholar
Wu, Z. K., Chen, Q. Q., Xiong, S. X., Xin, B., Zhao, Z. W., Jiang, L. J. & Ma, J. S. (2003). Angew. Chem. Int. Ed. 42, 3271–3274. Web of Science CSD CrossRef CAS Google Scholar