1-[4-(4-Isopropyl­phen­yl)-6-methyl-2-sulfanyl­idene-1,2,3,4-tetra­hydro­pyrimidin-5-yl]ethanone

N Anuradha; A Thiruvalluvar; S Chitra; D Devanathan; Oluwaseun O Falola; RJ Butcher

doi:10.1107/S1600536812034046

. 2012 Aug 4;68(Pt 9):o2641. doi: 10.1107/S1600536812034046

1-[4-(4-Isopropylphenyl)-6-methyl-2-sulfanylidene-1,2,3,4-tetrahydropyrimidin-5-yl]ethanone

N Anuradha ^a, A Thiruvalluvar ^a,^*, S Chitra ^b, D Devanathan ^c, Oluwaseun O Falola ^d, RJ Butcher ^d

PMCID: PMC3435669 PMID: 22969540

Abstract

In the title molecule, C₁₆H₂₀N₂OS, the heterocyclic ring adopts a slightly distorted flattened boat conformation, and the plane through the four coplanar atoms makes a dihedral angle of 86.98 (6)° with the benzene ring. The thione, acetyl and methyl groups lie on the opposite side of the heterocyclic mean plane to the isopropylphenyl group which has an axial orientation. A weak intramolecular C—H⋯O hydrogen bond is observed. In the crystal, molecules are linked via N—H⋯O, N—H⋯S and C—H⋯S hydrogen bonds.

Related literature

For chemical and biological applications and for the closely related crystal structures of the chloro and fluoro derivatives, see: Anuradha et al. (2009 ▶, 2012 ▶).

Experimental

Crystal data

C₁₆H₂₀N₂OS
M _r = 288.41
Monoclinic,
a = 26.8413 (5) Å
b = 9.5657 (2) Å
c = 12.0764 (2) Å
β = 90.370 (2)°
V = 3100.62 (10) Å³
Z = 8
Cu Kα radiation
μ = 1.83 mm⁻¹
T = 123 K
0.49 × 0.23 × 0.18 mm

Data collection

Oxford Diffraction Xcalibur Ruby Gemini diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012 ▶) T _min = 0.831, T _max = 1.000
5607 measured reflections
3042 independent reflections
2776 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.113
S = 1.05
3042 reflections
193 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.42 e Å⁻³
Δρ_min = −0.39 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812034046/wn2487sup1.cif

e-68-o2641-sup1.cif^{(20.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812034046/wn2487Isup2.hkl

e-68-o2641-Isup2.hkl^{(146.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812034046/wn2487Isup3.cdx

Supplementary material file. DOI: 10.1107/S1600536812034046/wn2487Isup4.cml

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
N1—H1⋯O51ⁱ	0.83 (2)	2.12 (2)	2.9445 (17)	174 (2)
N3—H3⋯S2ⁱⁱ	0.840 (19)	2.56 (2)	3.3481 (13)	156.9 (18)
C61—H61A⋯O51	0.98	2.22	2.9148 (19)	127
C61—H61B⋯S2ⁱⁱⁱ	0.98	2.86	3.7145 (16)	146

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

RJB acknowledges the NSF MRI program (grant No. CHE-0619278) for funds to purchase an X-ray diffractometer.

supplementary crystallographic information

Comment

As part of our investigations of dihydropyrimidine derivatives (Anuradha et al., 2009, 2012) to compare their chemical and biological activities, we have undertaken the X-ray crystal structure analysis of the title compound.

In the title molecule, C₁₆H₂₀N₂OS (Fig.1), the heterocyclic ring adopts a slightly distorted flattened boat conformation, and the plane through the four coplanar atoms( C2, N3, C5 and C6) makes a dihedral angle of 86.98 (6)° with the benzene ring. The thione, acetyl and methyl groups have equatorial orientations with respect to the attached heterocyclic ring, whereas the isopropylphenyl group has an axial orientation.

Intermolecular N1—H1···O51, N3—H3···S2 and C61—H61B···S2 hydrogen bonds are found in the crystal structure. A weak intramolecular C61—H61A···O51 hydrogen bond is also observed (Fig. 2, Table 1).

Experimental

A solution of acetylacetone (1.0012 g, 0.01 mol), 4-isopropylbenzaldehyde (1.48 g, 0.01 mol) and thiourea (1.14 g, 0.015 mol) was heated under reflux in the presence of calcium fluoride (0.07 g, 0.001 mol) for 2 h (monitored by TLC). After completion of the reaction, the reaction mixture was cooled to room temperature and poured into crushed ice. The solid product was filtered under suction and purified by recrystallization from hot methanol to give the product in pure form. Yield 1.86 g (93%).