organic compounds
N-(6-Amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)leucine: a three-dimensional hydrogen-bonded framework structure
aDepartamento de Química Inorgánica y Orgánica, Universidad de Jaén, 23071 Jaén, Spain, bDepartment of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE, Scotland, and cSchool of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland
*Correspondence e-mail: cg@st-andrews.ac.uk
In the title compound, C11H17N5O4, the bond distances show evidence of a highly polarized molecular–electronic structure. The molecules are linked into a three-dimensional framework by a combination of O—H⋯O and N—H⋯O hydrogen bonds, including a very short O—H⋯O hydrogen bond [H⋯O = 1.67 Å, O⋯O = 2.494 (2) Å and O—H⋯O = 166°].
Comment
We report here the structure of the title compound, (I), which we briefly compare with the structures of its valine, methionine and threonine analogues, (II)–(IV), respectively (Low et al., 1999, 2000), and those of the glycine, serine and isoleucine analogues, (V)–(VII), respectively, which all crystallize as hydrates (Low et al., 1997, 2000, 2001). Compound (I) thus differs from its isomer (VII), which forms a 4:1 hydrate of overall composition 4C11H17N5O4·H2O.
Within the molecule of (I) (Fig. 1), the bond distances (Table 1) in the heterocyclic ring and its immediate substituents are all very similar to the corresponding values in compounds (II)–(VII) and they provide evidence for extensive electronic polarization. In particular, the C5—N5 and N5—O5 distances in the C-nitroso group are very similar, the C4—C5 and C5—C6 bonds, which are formally single and double bonds, respectively, have distances identical within experimental uncertainly, and the C—N bonds involving atoms N1, N2 and N3, except for N2—C21, all have very similar distances, with the formally single C6—N6 bond shorter than the formally double N1=C2 bond. Taken together, these observations indicate a significant contribution to the overall molecular–electronic structure from the polarized form (Ia). The C—O distances in the carboxyl group are consistent with the location of the acidic H atom deduced from the difference maps.
The combination of the high negative change on the nitroso O atom and the carboxylic acid functionality leads to a very short O—H⋯O hydrogen bond (Table 2), which is also a feature of the analogues (II)–(VI), although not of (VII), where the carboxyl group acts as hydrogen-bond donor to the water molecule rather than to the nitroso O atom. The effect of the O—H⋯O hydrogen bond is to generate by translation a C(11) (Bernstein et al., 1995) chain running parallel to the [001] direction (Fig. 2). C(11) chains generated by translation also occur in (II)–(IV), while there are similar C(11) chains generated by a glide plane in (V) and by a 21 screw axis in (VI).
In addition, atom N2 in the molecule at (x, y, z) acts as a hydrogen-bond donor to atom O4 in the molecule at ( − x, 1 − y, + z), so forming a C(6) chain running parallel to the [001] direction and generated by the 21 screw axis along (, , z) (Fig. 2). The combination of the C(6) and C(11) chains along [001] generates a chain of edge-fused R33(17) rings (Fig. 2).
Amino atom N6 acts as a double donor of hydrogen bonds. In addition to forming the intramolecular S(6) motif characteristic of nitropyrimidine of this type, atom N6 in the molecule at (x, y, z) acts as donor, via atom H6B, to carboxyl atom O22 in the molecule at ( + x, − y, 1 − z), so forming a C(9) chain running parallel to the [100] direction and generated by the 21 screw axis along (x, , ) (Fig. 3). Thus, the intermolecular N—H⋯O hydrogen bond with N2 as donor, acting alone, forms a chain along [001], while that with N6 as donor, again acting alone, forms a chain along [100]. However, the combination of the two intermolecular N—H⋯O hydrogen bonds acting in concert forms a C44(26) chain running parallel to the [010] direction (Fig. 4). The combination of the [100], [010] and [001] chains then generates a continuous three-dimensional framework.
The anhydrous analogues (II)–(IV) all form three-dimensional hydrogen-bonded frameworks, but these differ in the details of their formation from the framework in (I) (Low et al., 1999, 2000). Similarly, the hydrates (V)–(VII) all form three-dimensional frameworks, again all of different construction (Low et al., 1997, 2000, 2001).
Experimental
The title compound was prepared by adding a suspension of 6-amino-3,4-dihydro-3-methyl-2-methoxy-5-nitroso-4-oxopyrimidine (5.00 g, 27.17 mmol) in acetonitrile (100 ml) to a suspension of L-leucine [(S)-2-amino-4-methylpentanoic acid; 3.90 g, 29.73 mmol] in aqueous KOH (60 ml of 0.5 M solution; 30.0 mmol). The mixture was stirred at 343 K for 1 h. The solution was then cooled to ambient temperature and the pH was adjusted to 3.0 by dropwise addition of aqueous HCl (0.1 M). After 8 h at room temperature, the orange crystalline solid which formed was collected by filtration and washed successively with water, ethanol and diethyl ether to yield the title compound (4.70 g, 16.60 mmol, 61%). Analysis found: C 45.9, H 5.6, N 25.1%; C11H17N5O4 requires: C 46.6, H, 6.0, N 24.7%.
Crystal data
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Refinement
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The P212121 was uniquely assigned from the All H atoms were located from difference maps and were subsequently treated as riding atoms, with C—H distances of 0.98 (CH3), 0.99 (CH2) or 1.00 Å (CH), N—H distances of 0.88 Å and O—H distances of 0.84 Å, and with Uiso(H) = 1.2Ueq(C,N), 1.5Ueq(C) for the methyl groups and 1.5Ueq(O). In the absence of significant the Flack (1983) parameter was indeterminate (Flack & Bernardinelli, 2000), and hence the Friedel-equivalent reflections were merged prior to the final refinements. The correct was set by reference to the known of the L-leucine employed in the synthesis.
Data collection: COLLECT (Hooft, 1999); cell DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
Supporting information
10.1107/S0108270105024406/sk1862sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S0108270105024406/sk1862Isup2.hkl
The title compound was prepared by adding a suspension of 6-amino-3,4-dihydro-3-methyl-2-methoxy-5-nitroso-4-oxopyrimidine (5.00 g, 27.17 mmol) in acetonitrile (100 ml) to a suspension of L-leucine [(S)-2-amino-4-methylpentanoic acid; 3.90 g, 29.73 mmol] in aqueous KOH (60 ml of 0.5 M solution; 30.0 mmol). The mixture was stirred at 343 K for 1 h. The solution was then cooled to ambient temperature and the pH was adjusted to 3.0 by dropwise addition of aqueous HCl (0.1 M). After 8 h at room temperature, the orange crystalline solid which formed was collected by filtration and washed successively with water, ethanol and diethyl ether to yield the title compound (4.70 g, 16.60 mmol, 61%). Analysis: found C 45.9, H 5.6, N 25.1%; C11H17N5O4 requires C 46.6, H, 6.0, N 24.7%.
The
P212121 was uniquely assigned from the All H atoms were located from difference maps and were subsequently treated as riding atoms, with C—H distances of 0.98 Å (CH3), 0.99 Å (CH2) or 1.00 Å (CH), N—H distances of 0.88 Å and O—H distances of 0.84 Å, and with Uiso(H) = 1.2Ueq(C,N), or 1.5Ueq(C) for the methyl groups, and 1.5Ueq(O). In the absence of significant the (Flack, 1983) was indeterminate (Flack & Bernardinelli, 2000), and hence the Friedel-equivalent reflections were merged prior to the final refinements. The correct was set by reference to the known of the L-leucine employed in the synthesis.Data collection: COLLECT (Hooft, 1999); cell
DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).C11H17N5O4 | F(000) = 600 |
Mr = 283.30 | Dx = 1.383 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 1795 reflections |
a = 9.4395 (2) Å | θ = 3.2–27.5° |
b = 13.1565 (3) Å | µ = 0.11 mm−1 |
c = 10.9581 (2) Å | T = 120 K |
V = 1360.89 (5) Å3 | Lath, orange |
Z = 4 | 0.20 × 0.10 × 0.08 mm |
Nonius KappaCCD area-detector diffractometer | 1795 independent reflections |
Radiation source: Bruker Nonius FR91 rotating anode | 1644 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
Detector resolution: 9.091 pixels mm-1 | θmax = 27.5°, θmin = 3.2° |
ϕ and ω scans | h = −12→12 |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | k = −17→16 |
Tmin = 0.982, Tmax = 0.992 | l = −14→14 |
22570 measured reflections |
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)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0702P)2 + 0.2932P] where P = (Fo2 + 2Fc2)/3 |
1795 reflections | (Δ/σ)max = 0.001 |
185 parameters | Δρmax = 0.32 e Å−3 |
0 restraints | Δρmin = −0.30 e Å−3 |
C11H17N5O4 | V = 1360.89 (5) Å3 |
Mr = 283.30 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 9.4395 (2) Å | µ = 0.11 mm−1 |
b = 13.1565 (3) Å | T = 120 K |
c = 10.9581 (2) Å | 0.20 × 0.10 × 0.08 mm |
Nonius KappaCCD area-detector diffractometer | 1795 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | 1644 reflections with I > 2σ(I) |
Tmin = 0.982, Tmax = 0.992 | Rint = 0.024 |
22570 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.32 e Å−3 |
1795 reflections | Δρmin = −0.30 e Å−3 |
185 parameters |
x | y | z | Uiso*/Ueq | ||
O4 | 0.17512 (16) | 0.42095 (12) | 0.10904 (13) | 0.0204 (3) | |
O5 | 0.44571 (17) | 0.22692 (12) | −0.04938 (13) | 0.0223 (3) | |
O21 | 0.52219 (17) | 0.26060 (13) | 0.73658 (14) | 0.0267 (4) | |
O22 | 0.31846 (16) | 0.33891 (12) | 0.68781 (14) | 0.0228 (3) | |
N1 | 0.48741 (18) | 0.29307 (13) | 0.31541 (15) | 0.0169 (4) | |
N2 | 0.41713 (17) | 0.39787 (13) | 0.47036 (15) | 0.0168 (4) | |
N3 | 0.28601 (17) | 0.40236 (13) | 0.29227 (15) | 0.0163 (4) | |
N5 | 0.36042 (19) | 0.29343 (14) | −0.00210 (16) | 0.0189 (4) | |
N6 | 0.56944 (19) | 0.19659 (14) | 0.15928 (16) | 0.0197 (4) | |
C2 | 0.3981 (2) | 0.36236 (16) | 0.35723 (18) | 0.0156 (4) | |
C3 | 0.1785 (2) | 0.46433 (17) | 0.35373 (19) | 0.0199 (4) | |
C4 | 0.2697 (2) | 0.38014 (15) | 0.16743 (18) | 0.0160 (4) | |
C5 | 0.3696 (2) | 0.30631 (16) | 0.11780 (18) | 0.0163 (4) | |
C6 | 0.4761 (2) | 0.26289 (15) | 0.19851 (18) | 0.0160 (4) | |
C21 | 0.5202 (2) | 0.35525 (16) | 0.55548 (18) | 0.0171 (4) | |
C22 | 0.4411 (2) | 0.31676 (16) | 0.66712 (18) | 0.0192 (4) | |
C23 | 0.6301 (2) | 0.43523 (18) | 0.5961 (2) | 0.0226 (5) | |
C24 | 0.7219 (2) | 0.47950 (19) | 0.4938 (2) | 0.0312 (6) | |
C25 | 0.8003 (3) | 0.3981 (2) | 0.4241 (3) | 0.0403 (7) | |
C26 | 0.8255 (3) | 0.5559 (2) | 0.5493 (3) | 0.0466 (8) | |
H2 | 0.3650 | 0.4495 | 0.4947 | 0.020* | |
H3A | 0.1412 | 0.4271 | 0.4242 | 0.030* | |
H3B | 0.1011 | 0.4791 | 0.2968 | 0.030* | |
H3C | 0.2213 | 0.5282 | 0.3813 | 0.030* | |
H6A | 0.6356 | 0.1739 | 0.2089 | 0.024* | |
H6B | 0.5659 | 0.1748 | 0.0834 | 0.024* | |
H21 | 0.5703 | 0.2971 | 0.5156 | 0.021* | |
H21A | 0.4832 | 0.2525 | 0.8048 | 0.040* | |
H23A | 0.5793 | 0.4918 | 0.6366 | 0.027* | |
H23B | 0.6933 | 0.4038 | 0.6576 | 0.027* | |
H24 | 0.6587 | 0.5165 | 0.4355 | 0.037* | |
H25A | 0.8619 | 0.4299 | 0.3630 | 0.060* | |
H25B | 0.7320 | 0.3535 | 0.3832 | 0.060* | |
H25C | 0.8580 | 0.3581 | 0.4808 | 0.060* | |
H26A | 0.8935 | 0.5200 | 0.6014 | 0.070* | |
H26B | 0.7731 | 0.6056 | 0.5983 | 0.070* | |
H26C | 0.8765 | 0.5912 | 0.4839 | 0.070* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O4 | 0.0167 (7) | 0.0240 (8) | 0.0205 (7) | 0.0030 (6) | −0.0045 (6) | 0.0027 (6) |
O5 | 0.0255 (7) | 0.0265 (8) | 0.0149 (7) | 0.0055 (6) | −0.0004 (6) | −0.0023 (6) |
O21 | 0.0243 (8) | 0.0404 (10) | 0.0155 (7) | 0.0082 (8) | 0.0022 (6) | 0.0064 (7) |
O22 | 0.0168 (7) | 0.0303 (8) | 0.0212 (7) | −0.0001 (6) | 0.0043 (6) | 0.0025 (7) |
N1 | 0.0144 (8) | 0.0219 (8) | 0.0144 (7) | 0.0028 (7) | −0.0015 (7) | −0.0001 (7) |
N2 | 0.0134 (8) | 0.0223 (8) | 0.0147 (8) | 0.0031 (7) | −0.0008 (7) | −0.0004 (7) |
N3 | 0.0105 (8) | 0.0219 (8) | 0.0164 (8) | 0.0023 (7) | −0.0006 (7) | −0.0011 (7) |
N5 | 0.0181 (8) | 0.0222 (9) | 0.0164 (8) | 0.0005 (7) | −0.0010 (7) | −0.0008 (8) |
N6 | 0.0181 (9) | 0.0262 (9) | 0.0147 (8) | 0.0068 (7) | −0.0047 (7) | −0.0018 (7) |
C2 | 0.0124 (9) | 0.0198 (10) | 0.0145 (9) | −0.0004 (8) | 0.0010 (7) | 0.0015 (8) |
C3 | 0.0141 (9) | 0.0254 (11) | 0.0202 (10) | 0.0049 (8) | 0.0006 (8) | 0.0006 (8) |
C4 | 0.0133 (9) | 0.0196 (10) | 0.0151 (9) | −0.0028 (8) | −0.0013 (8) | 0.0028 (8) |
C5 | 0.0135 (9) | 0.0211 (10) | 0.0144 (9) | −0.0007 (8) | 0.0015 (8) | 0.0027 (8) |
C6 | 0.0131 (9) | 0.0205 (10) | 0.0144 (9) | 0.0002 (8) | −0.0005 (8) | 0.0013 (8) |
C21 | 0.0132 (9) | 0.0241 (10) | 0.0141 (9) | 0.0018 (8) | −0.0020 (8) | −0.0010 (8) |
C22 | 0.0193 (10) | 0.0238 (11) | 0.0145 (9) | −0.0010 (8) | −0.0011 (8) | −0.0025 (8) |
C23 | 0.0159 (9) | 0.0286 (11) | 0.0234 (11) | −0.0010 (9) | −0.0022 (8) | −0.0063 (9) |
C24 | 0.0191 (12) | 0.0346 (13) | 0.0400 (14) | −0.0052 (10) | 0.0013 (11) | 0.0011 (12) |
C25 | 0.0253 (12) | 0.0529 (17) | 0.0426 (15) | −0.0084 (12) | 0.0119 (12) | −0.0090 (13) |
C26 | 0.0301 (14) | 0.0379 (15) | 0.072 (2) | −0.0082 (12) | 0.0000 (15) | −0.0057 (15) |
N1—C2 | 1.324 (3) | O21—H21A | 0.84 |
C2—N3 | 1.379 (2) | C23—C24 | 1.532 (3) |
N3—C4 | 1.407 (2) | C23—H23A | 0.99 |
C4—C5 | 1.459 (3) | C23—H23B | 0.99 |
C5—C6 | 1.455 (3) | C24—C25 | 1.509 (4) |
C6—N1 | 1.345 (2) | C24—C26 | 1.529 (4) |
C22—O21 | 1.308 (3) | C24—H24 | 1.00 |
C2—N2 | 1.337 (3) | C25—H25A | 0.98 |
N3—C3 | 1.466 (3) | C25—H25B | 0.98 |
C4—O4 | 1.222 (2) | C25—H25C | 0.98 |
C5—N5 | 1.328 (3) | C26—H26A | 0.98 |
N5—O5 | 1.297 (2) | C26—H26B | 0.98 |
C6—N6 | 1.312 (3) | C26—H26C | 0.98 |
C22—O22 | 1.215 (3) | C3—H3A | 0.98 |
N2—C21 | 1.460 (2) | C3—H3B | 0.98 |
N2—H2 | 0.88 | C3—H3C | 0.98 |
C21—C22 | 1.520 (3) | N6—H6A | 0.88 |
C21—C23 | 1.543 (3) | N6—H6B | 0.88 |
C21—H21 | 1.00 | ||
C2—N1—C6 | 118.83 (17) | C24—C25—H25C | 109.5 |
N1—C2—N2 | 118.42 (18) | H25A—C25—H25C | 109.5 |
N1—C2—N3 | 124.94 (18) | H25B—C25—H25C | 109.5 |
N2—C2—N3 | 116.64 (18) | C24—C26—H26A | 109.5 |
C2—N2—C21 | 123.23 (17) | C24—C26—H26B | 109.5 |
C2—N2—H2 | 118.4 | H26A—C26—H26B | 109.5 |
C21—N2—H2 | 118.4 | C24—C26—H26C | 109.5 |
N2—C21—C22 | 108.35 (16) | H26A—C26—H26C | 109.5 |
N2—C21—C23 | 111.74 (17) | H26B—C26—H26C | 109.5 |
C22—C21—C23 | 108.98 (16) | C2—N3—C4 | 120.43 (17) |
N2—C21—H21 | 109.2 | C2—N3—C3 | 120.40 (16) |
C22—C21—H21 | 109.2 | C4—N3—C3 | 119.10 (16) |
C23—C21—H21 | 109.2 | N3—C3—H3A | 109.5 |
C22—O21—H21A | 109.5 | N3—C3—H3B | 109.5 |
O22—C22—O21 | 125.8 (2) | H3A—C3—H3B | 109.5 |
O22—C22—C21 | 122.6 (2) | N3—C3—H3C | 109.5 |
O21—C22—C21 | 111.67 (18) | H3A—C3—H3C | 109.5 |
C24—C23—C21 | 115.36 (18) | H3B—C3—H3C | 109.5 |
C24—C23—H23A | 108.4 | O4—C4—N3 | 119.84 (19) |
C21—C23—H23A | 108.4 | O4—C4—C5 | 124.71 (18) |
C24—C23—H23B | 108.4 | N3—C4—C5 | 115.44 (17) |
C21—C23—H23B | 108.4 | N5—C5—C6 | 126.6 (2) |
H23A—C23—H23B | 107.5 | N5—C5—C4 | 114.29 (18) |
C25—C24—C26 | 110.7 (2) | C6—C5—C4 | 118.77 (17) |
C25—C24—C23 | 112.2 (2) | O5—N5—C5 | 116.16 (19) |
C26—C24—C23 | 108.7 (2) | N6—C6—N1 | 117.04 (18) |
C25—C24—H24 | 108.4 | N6—C6—C5 | 121.70 (18) |
C26—C24—H24 | 108.4 | N1—C6—C5 | 121.17 (18) |
C23—C24—H24 | 108.4 | C6—N6—H6A | 120.0 |
C24—C25—H25A | 109.5 | C6—N6—H6B | 120.0 |
C24—C25—H25B | 109.5 | H6A—N6—H6B | 120.0 |
H25A—C25—H25B | 109.5 | ||
C6—N1—C2—N2 | −174.70 (18) | N2—C2—N3—C3 | −12.0 (3) |
C6—N1—C2—N3 | 4.6 (3) | C2—N3—C4—O4 | −175.51 (18) |
N1—C2—N2—C21 | −7.9 (3) | C3—N3—C4—O4 | 7.6 (3) |
N3—C2—N2—C21 | 172.75 (17) | C2—N3—C4—C5 | 5.5 (3) |
C2—N2—C21—C22 | −119.5 (2) | C3—N3—C4—C5 | −171.45 (17) |
C2—N2—C21—C23 | 120.4 (2) | O4—C4—C5—N5 | 6.8 (3) |
N2—C21—C22—O22 | −13.7 (3) | N3—C4—C5—N5 | −174.26 (18) |
C23—C21—C22—O22 | 108.1 (2) | O4—C4—C5—C6 | −179.3 (2) |
N2—C21—C22—O21 | 167.89 (17) | N3—C4—C5—C6 | −0.3 (3) |
C23—C21—C22—O21 | −70.3 (2) | C6—C5—N5—O5 | 7.9 (3) |
N2—C21—C23—C24 | −61.9 (2) | C4—C5—N5—O5 | −178.71 (16) |
C22—C21—C23—C24 | 178.39 (19) | C2—N1—C6—N6 | 177.82 (19) |
C21—C23—C24—C25 | −56.5 (3) | C2—N1—C6—C5 | 1.1 (3) |
C21—C23—C24—C26 | −179.32 (19) | N5—C5—C6—N6 | −6.5 (3) |
N1—C2—N3—C4 | −8.1 (3) | C4—C5—C6—N6 | −179.61 (19) |
N2—C2—N3—C4 | 171.14 (18) | N5—C5—C6—N1 | 170.1 (2) |
N1—C2—N3—C3 | 168.75 (19) | C4—C5—C6—N1 | −3.0 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O21—H21A···O5i | 0.84 | 1.67 | 2.494 (2) | 166 |
N2—H2···O4ii | 0.88 | 2.15 | 2.958 (2) | 153 |
N6—H6A···O22iii | 0.88 | 2.07 | 2.924 (2) | 163 |
N6—H6B···O5 | 0.88 | 1.97 | 2.598 (2) | 127 |
Symmetry codes: (i) x, y, z+1; (ii) −x+1/2, −y+1, z+1/2; (iii) x+1/2, −y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C11H17N5O4 |
Mr | 283.30 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 120 |
a, b, c (Å) | 9.4395 (2), 13.1565 (3), 10.9581 (2) |
V (Å3) | 1360.89 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.20 × 0.10 × 0.08 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2003) |
Tmin, Tmax | 0.982, 0.992 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 22570, 1795, 1644 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.106, 1.06 |
No. of reflections | 1795 |
No. of parameters | 185 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.32, −0.30 |
Computer programs: COLLECT (Hooft, 1999), DENZO (Otwinowski & Minor, 1997) and COLLECT, DENZO and COLLECT, OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997), OSCAIL and SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), SHELXL97 and PRPKAPPA (Ferguson, 1999).
N1—C2 | 1.324 (3) | C2—N2 | 1.337 (3) |
C2—N3 | 1.379 (2) | N3—C3 | 1.466 (3) |
N3—C4 | 1.407 (2) | C4—O4 | 1.222 (2) |
C4—C5 | 1.459 (3) | C5—N5 | 1.328 (3) |
C5—C6 | 1.455 (3) | N5—O5 | 1.297 (2) |
C6—N1 | 1.345 (2) | C6—N6 | 1.312 (3) |
C22—O21 | 1.308 (3) | C22—O22 | 1.215 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O21—H21A···O5i | 0.84 | 1.67 | 2.494 (2) | 166 |
N2—H2···O4ii | 0.88 | 2.15 | 2.958 (2) | 153 |
N6—H6A···O22iii | 0.88 | 2.07 | 2.924 (2) | 163 |
N6—H6B···O5 | 0.88 | 1.97 | 2.598 (2) | 127 |
Symmetry codes: (i) x, y, z+1; (ii) −x+1/2, −y+1, z+1/2; (iii) x+1/2, −y+1/2, −z+1. |
Acknowledgements
The X-ray data were collected at the EPSRC X-ray Crystallographic Service, University of Southampton, England.
References
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Ferguson, G. (1999). PRPKAPPA. University of Guelph, Canada. Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Flack, H. D. & Bernardinelli, G. (2000). J. Appl. Cryst. 33, 1143–1148. Web of Science CrossRef CAS IUCr Journals Google Scholar
Hooft, R. W. W. (1999). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Low, J. N., Cannon, D., Quesada, A., Marchal, A., Melguizo, M., Nogueras, M., Sánchez, A. & Glidewell, C. (2001). Acta Cryst. C57, 604–607. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Low, J. N., Ferguson, G., López, R., Arranz, P., Cobo, J., Melguizo, M., Nogueras, M. & Sánchez, A. (1997). Acta Cryst. C53, 890–892. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Low, J. N., Godino, M. L., López, R., Pérez, A., Melguizo, M. & Cobo, J. (1999). Acta Cryst. C55, 1727–1730. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Low, J. N., López. M. D., Arranz Mascarós, P., Cobo Domingo, J., Godino, M. L., López Garzón, R., Gutiérrez, M. D., Melguizo, M., Ferguson, G. & Glidewell, C. (2000). Acta Cryst. B56, 882–892. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
McArdle, P. (2003). OSCAIL for Windows. Version 10. Crystallography Centre, Chemistry Department, NUI Galway, Ireland. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2003). SADABS. Version 2.10. University of Göttingen, Germany. Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar
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We report here the structure of the title compound, (I), which we briefly compare with the structures of its valine, methionine and threonine analogues, (II)–(IV), respectively (Low et al., 1999, 2000), and those of the glycine, serine and isoleucine analogues, (V)–(VII), respectively, which all crystallize as hydrates (Low et al., 1997, 2000, 2001). Compound (I) thus differs from its isomer (VII), which forms a 4:1 hydrate of overall composition (C11H17N5O4)4·H2O.
Within the molecule of (I) (Fig. 1), the bond distances (Table 1) in the heterocyclic ring and its immediate substituents are all very similar to the corresponding values in compounds (II)–(VII) and they provide evidence for extensive electronic polarization. In particular, the C5—N5 and N5—O5 distances in the C-nitroso group are very similar, the C4—C5 and C5—C6 bonds, which are formally single and double bonds, respectively, have distances identical within experimental uncertainly, and the C—N bonds involving atoms N1, N2 and N3, except for N2—C21, all have very similar distances, with the formally single C6—N6 bond shorter than the formally double N1—C2 bond. Taken together, these observations indicate a significant contribution to the overall molecular-electronic structure from the polarized form (Ia). The C—O distances in the carboxyl group are consistent with the location of the acidic H atom deduced from the difference maps.
The combination of the high negative change on the nitroso O atom and the carboxylic acid functionality leads to a very short O—H···O hydrogen bond (Table 2), which is also a feature of the analogues (II)–(VI), although not of (VII), where the carboxyl group acts as hydrogen-bond donor to the water molecule rather than to the nitroso O atom. The effect of the O—H···O hydrogen bond is to generate by translation a C(11) (Bernstein et al., 1995) chain running parallel to the [001] direction (Fig. 2). C(11) chains generated by translation also occur in (II)–(IV), while there are similar C(11) chains generated by a glide plane in (V) and by a 21 screw axis in (VI).
In addition, atom N2 in the molecule at (x, y, z) acts as hydrogen-bond donor to atom O4 in the molecule at (1/2 − x, 1 − y, 1/2 + z), so forming a C(6) chain running parallel to the [001] direction and generated by the 21 screw axis along (1/4, 1/2, z) (Fig. 2). The combination of the C(6) and C(11) chains along [001] generates a chain of edge-fused R33(17) rings (Fig. 2).
The amino atom N6 acts as a double donor of hydrogen bonds. In addition to forming the intramolecular S(6) motif characteristic of nitropyrimidine of this type, atom N6 in the molecule at (x, y, z) acts as donor, via atom H6B, to carboxyl atom O22 in the molecule at (1/2 + x, 1/2 − y, 1 − z), so forming a C(9) chain running parallel to the [100] direction and generated by the 21 screw axis along (x, 1/4, 1/2) (Fig. 3). Thus, the intermolecular N—H···O hydrogen bond with N2 as donor, acting alone, forms a chain along [001], while that with N6 as donor, again acting alone, forms a chain along [100]. However, the combination of the two intermolecular N—H···O hydrogen bonds acting in concert forms a C22(13) chain running parallel to the [010] direction (Fig. 4). The combination of the [100], [010] and [001] chains then generates a continuous three-dimensional framework.
The anhydrous analogues (II)–(IV) all form three-dimensional hydrogen-bonded frameworks, but these differ in the details of their formation from the framework in (I) (Low et al., 1999, 2000). Similarly, the hydrates (V)–(VII) all form three-dimensional frameworks, again all of different construction (Low et al., 1997, 2000, 2001).