2-Methyl-4-oxo-6,7,8,9-tetrahydro­thieno[2′,3′:4,5]pyrimidino­[1,2-a]pyridine-3-carboxylic acid

Burkhon Zh Elmuradov; Khurshed A Bozorov; Rasul Ya Okmanov; Bakhodir Tashkhodjaev; Khusnutdin M Shakhidoyatov

doi:10.1107/S1600536811007902

. 2011 Mar 9;67(Pt 4):o824. doi: 10.1107/S1600536811007902

2-Methyl-4-oxo-6,7,8,9-tetrahydrothieno[2′,3′:4,5]pyrimidino[1,2-a]pyridine-3-carboxylic acid

Burkhon Zh Elmuradov ^a,^*, Khurshed A Bozorov ^a, Rasul Ya Okmanov ^a, Bakhodir Tashkhodjaev ^a, Khusnutdin M Shakhidoyatov ^a

PMCID: PMC3099994 PMID: 21754108

Abstract

There are two independent molecules in the asymmetric unit of the title compound, C₁₂H₁₂N₂O₃S. With the exception of the methylene groups, a mean plane fitted through all non-H atoms of each molecule has an r.m.s. deviation of 0.035 Å for one molecule and 0.120 Å for the second. In one of the independent molecules, the methylene groups was refined using a disorder model with an occupancy ratio of 0.53:0.47 (14). Each molecule features an intramolecular O—H⋯O hydrogen bond, which generates an S(7) ring.

Related literature

For the synthesis of thieno[2,3-d]pyrimidin-4-ones and their derivatives, see: Litvinov (2004 ▶); Elmuradov et al. (2010 ▶); Csukonyi et al. (1986 ▶). For the physiological activity of thieno[2,3-d]pyrimidin-4-ones and their derivatives, see: Lilienkampf et al. (2007 ▶). For a related structure, see: Bozorov et al. (2010 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₂H₁₂N₂O₃S
M _r = 264.30
Monoclinic,
a = 7.2550 (15) Å
b = 20.506 (4) Å
c = 15.824 (3) Å
β = 96.93 (3)°
V = 2337.0 (8) Å³
Z = 8
Cu Kα radiation
μ = 2.50 mm⁻¹
T = 296 K
0.60 × 0.40 × 0.15 mm

Data collection

Stoe STADI4 diffractometer
Absorption correction: ψ scan (Blessing, 1987 ▶) T _min = 0.346, T _max = 0.687
4297 measured reflections
3438 independent reflections
2420 reflections with I > 2σ(I)
R _int = 0.047
θ_max = 60.0°
3 standard reflections every 60 min intensity decay: 4.7%

Refinement

R[F ² > 2σ(F ²)] = 0.063
wR(F ²) = 0.169
S = 1.10
3438 reflections
348 parameters
23 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: STADI4 (Stoe & Cie, 1997 ▶); cell refinement: STADI4; data reduction: X-RED (Stoe & Cie, 1997 ▶); 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: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811007902/nk2082sup1.cif

e-67-0o824-sup1.cif^{(29.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811007902/nk2082Isup2.hkl

e-67-0o824-Isup2.hkl^{(168.6KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2O⋯O1	0.87 (2)	1.63 (2)	2.501 (5)	177 (7)
O52—H52O⋯O51	0.87 (2)	1.71 (3)	2.518 (6)	154 (4)

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Acknowledgments

We thank the Academy of Sciences of the Republic of Uzbekistan for supporting this study (grants FA-F3-T045 and FA-F3-T047)

supplementary crystallographic information

Comment

Among heterocyclic compounds. the thieno[2,3-d]pyrimidin-4-one family (Litvinov, 2004; Elmuradov et al., 2010; Csukonyi et al., 1986) has been shown to possess various physiological activity (Lilienkampf et al., 2007). The reaction of 2,3-dimethylthieno[2',3':4,5]pyrimidino[1,2-a]pyridin-4-one with nitric acid in ratio of reagents - substrate:HNO₃ - 1:4 in concentrated sulfuric acid leads to the formation of 3-hydroxycarbonyl-2- methylthieno[2',3':4,5]pyrimidino[1,2-a]pyridin-4-one (Figure 1). We report here the synthesis and crystal structure.

The asymmetric unit contains two crystallographically unique molecules (Figure 2). With the exception of the methylene group, a mean plane fitted through all non-H atoms of each molecule has an rms deviation of 0.035 for one molecule, and 0.120 for the second. In one of the unique molecules the methylene group was refined using a disorder model with an occupancy ratio of 0.53:0.47 (14). An S(7) intramolecular O—H···O hydrogen bond is observed in each unique molecule (Bernstein et al., 1995).

Experimental

Into a flask supplied with a mixer was poured 2 ml H₂SO₄ and cooled by an ice bath (0.25 h). Then 1 g (4.26 mmole) 2,3-dimethylthieno[2',3':4,5]pyrimidino[1,2-a]pyridin-4-one was added in portions, mixed before complete dissolution, nitrating acid consisting of 1.89 g (1.4 ml, d═1.35 g/ml) (17.08 mmole) HNO₃ and 1.4 ml (d═1.835 g/ml) H₂SO₄ were added (0.5 h) drop wise. A reactionary mixture were mixed 1 h at room temperature and left 2 days at room temperature and a mixture is decomposed in cold. The formed yellow crystals were filtered off and washed with water and dried. Yield 1.0 g (89%), m.p. 478–479 K (ethanol). The yellow crystals suitable for X-ray analysis were obtained from absolute methanol at room temperature.