organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

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

aPG Research Department of Physics, Rajah Serfoji Government College (Autonomous), Thanjavur 613 005, Tamilnadu, India, bDepartment of Chemistry, K.S.R. College of Engineering, K.S.R. Kalvi Nagar, Tiruchengode 637 215, Tamilnadu, India, cDepartment of Chemistry, Government Arts College, C. Mutlur 608 102, Chidambaram, Tamilnadu, India, and dDepartment of Chemistry, Howard University, 525 College Street NW, Washington, DC 20059, USA
*Correspondence e-mail: thiruvalluvar.a@gmail.com

(Received 29 July 2012; accepted 30 July 2012; online 4 August 2012)

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[Anuradha, N., Thiruvalluvar, A., Pandiarajan, K., Chitra, S. & Butcher, R. J. (2009). Acta Cryst. E65, o564-o565.], 2012[Anuradha, N., Thiruvalluvar, A., Chitra, S., Devanathan, D. & Butcher, R. J. (2012). Acta Cryst. E68, o2625.]).

[Scheme 1]

Experimental

Crystal data
  • C16H20N2OS

  • Mr = 288.41

  • Monoclinic, C 2/c

  • 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[Agilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.]) Tmin = 0.831, Tmax = 1.000

  • 5607 measured reflections

  • 3042 independent reflections

  • 2776 reflections with I > 2σ(I)

  • Rint = 0.024

Refinement
  • R[F2 > 2σ(F2)] = 0.041

  • wR(F2) = 0.113

  • S = 1.05

  • 3042 reflections

  • 193 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.42 e Å−3

  • Δρmin = −0.39 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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
Symmetry codes: (i) [x, -y+1, z-{\script{1\over 2}}]; (ii) -x, -y, -z; (iii) -x, -y+1, -z.

Data collection: CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: PLATON.

Supporting information


Comment top

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).

Related literature top

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 top

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%).

Refinement top

The two N-bound H atoms were located in a difference Fourier map and refined freely; N1—H1 = 0.83 (2) Å and N3—H3 = 0.840 (19) Å. The remaining H atoms were positioned geometrically and allowed to ride on their parent atoms, with Csp2—H = 0.95, C(methyl)—H = 0.98, and C(methine)—H = 1.00 Å; Uiso(H) = kUeq(C), where k = 1.5 for methyl H and 1.2 for all other H atoms.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); 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 (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with displacement ellipsoids drawn at the 30% probability level. H atoms are shown as small spheres of arbitrary radius. Dashed lines indicate the intramolecular C—H···O hydrogen bond.
[Figure 2] Fig. 2. The packing of the title compound, viewed down the b axis. Dashed lines indicate hydrogen bonds. H atoms not involved in hydrogen bonding have been omitted.
1-[4-(4-Isopropylphenyl)-6-methyl-2-sulfanylidene-1,2,3,4- tetrahydropyrimidin-5-yl]ethanone top
Crystal data top
C16H20N2OSF(000) = 1232
Mr = 288.41Dx = 1.236 Mg m3
Monoclinic, C2/cMelting point: 486 K
Hall symbol: -C 2ycCu Kα radiation, λ = 1.54184 Å
a = 26.8413 (5) ÅCell parameters from 3841 reflections
b = 9.5657 (2) Åθ = 3.3–73.5°
c = 12.0764 (2) ŵ = 1.83 mm1
β = 90.370 (2)°T = 123 K
V = 3100.62 (10) Å3Prism, colourless
Z = 80.49 × 0.23 × 0.18 mm
Data collection top
Oxford Diffraction Xcalibur Ruby Gemini
diffractometer
3042 independent reflections
Radiation source: Enhance (Cu) X-ray Source2776 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
Detector resolution: 10.5081 pixels mm-1θmax = 73.6°, θmin = 3.3°
ω scansh = 3033
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2012)
k = 1110
Tmin = 0.831, Tmax = 1.000l = 1014
5607 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.113H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.0684P)2 + 1.9078P]
where P = (Fo2 + 2Fc2)/3
3042 reflections(Δ/σ)max = 0.001
193 parametersΔρmax = 0.42 e Å3
0 restraintsΔρmin = 0.39 e Å3
Crystal data top
C16H20N2OSV = 3100.62 (10) Å3
Mr = 288.41Z = 8
Monoclinic, C2/cCu Kα radiation
a = 26.8413 (5) ŵ = 1.83 mm1
b = 9.5657 (2) ÅT = 123 K
c = 12.0764 (2) Å0.49 × 0.23 × 0.18 mm
β = 90.370 (2)°
Data collection top
Oxford Diffraction Xcalibur Ruby Gemini
diffractometer
3042 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2012)
2776 reflections with I > 2σ(I)
Tmin = 0.831, Tmax = 1.000Rint = 0.024
5607 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.113H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.42 e Å3
3042 reflectionsΔρmin = 0.39 e Å3
193 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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 > 2σ(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
xyzUiso*/Ueq
S20.02408 (1)0.17969 (4)0.10663 (3)0.0195 (1)
O510.05759 (4)0.41789 (12)0.40606 (9)0.0236 (3)
N10.05834 (5)0.34011 (14)0.05675 (10)0.0163 (3)
N30.04445 (5)0.11271 (13)0.10324 (10)0.0174 (3)
C20.04342 (5)0.20984 (16)0.02461 (12)0.0157 (4)
C40.07362 (5)0.12832 (15)0.20639 (12)0.0163 (4)
C50.06781 (5)0.27819 (15)0.24566 (12)0.0148 (4)
C60.06273 (5)0.37919 (15)0.16783 (12)0.0154 (4)
C140.27761 (7)0.0514 (2)0.10895 (16)0.0335 (6)
C150.28259 (8)0.0600 (2)0.01678 (18)0.0417 (7)
C160.31816 (8)0.0428 (3)0.1572 (2)0.0553 (8)
C410.12759 (6)0.08478 (16)0.18712 (12)0.0184 (4)
C420.14242 (7)0.05178 (17)0.20769 (14)0.0255 (5)
C430.19116 (7)0.09414 (18)0.18449 (15)0.0294 (5)
C440.22550 (6)0.00268 (19)0.14005 (14)0.0268 (5)
C450.21077 (7)0.1352 (2)0.12272 (17)0.0336 (6)
C460.16255 (7)0.17846 (18)0.14600 (16)0.0295 (5)
C510.07174 (5)0.30757 (16)0.36521 (12)0.0172 (4)
C520.09518 (7)0.19628 (17)0.43753 (13)0.0238 (4)
C610.06312 (6)0.53426 (16)0.18341 (13)0.0205 (4)
H10.0578 (8)0.404 (2)0.0103 (18)0.027 (5)*
H30.0331 (8)0.033 (2)0.0883 (16)0.022 (5)*
H40.059080.064990.263600.0195*
H140.282520.147490.139780.0401*
H15A0.256740.121990.046730.0625*
H15B0.315510.097160.035470.0625*
H15C0.278720.033490.048810.0625*
H16A0.314390.137440.127360.0829*
H16B0.350960.005850.137320.0829*
H16C0.315170.045450.238040.0829*
H420.119390.116790.237640.0305*
H430.200840.187770.199630.0353*
H450.234070.200680.094520.0403*
H460.153350.273120.133700.0353*
H52A0.094050.225940.515150.0357*
H52B0.129920.182300.415610.0357*
H52C0.076780.108450.428720.0357*
H61A0.070080.556100.261270.0308*
H61B0.030560.572630.162340.0308*
H61C0.088980.575680.136810.0308*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S20.0271 (2)0.0143 (2)0.0171 (2)0.0000 (1)0.0027 (1)0.0011 (1)
O510.0312 (6)0.0183 (6)0.0212 (5)0.0007 (5)0.0029 (4)0.0047 (4)
N10.0205 (6)0.0117 (6)0.0168 (6)0.0001 (5)0.0005 (5)0.0016 (5)
N30.0226 (6)0.0101 (6)0.0194 (6)0.0027 (5)0.0022 (5)0.0006 (5)
C20.0159 (7)0.0132 (7)0.0181 (7)0.0017 (5)0.0011 (5)0.0003 (5)
C40.0190 (7)0.0129 (7)0.0169 (7)0.0008 (5)0.0005 (5)0.0009 (5)
C50.0143 (6)0.0123 (7)0.0179 (7)0.0000 (5)0.0005 (5)0.0011 (5)
C60.0123 (6)0.0145 (7)0.0195 (7)0.0000 (5)0.0009 (5)0.0023 (5)
C140.0285 (9)0.0315 (10)0.0404 (10)0.0150 (8)0.0036 (7)0.0022 (8)
C150.0407 (11)0.0405 (12)0.0440 (11)0.0109 (9)0.0115 (9)0.0081 (9)
C160.0253 (10)0.0666 (16)0.0738 (16)0.0188 (10)0.0064 (10)0.0274 (13)
C410.0212 (7)0.0157 (7)0.0183 (7)0.0032 (6)0.0008 (5)0.0001 (5)
C420.0310 (8)0.0164 (8)0.0291 (8)0.0032 (7)0.0035 (6)0.0025 (6)
C430.0355 (9)0.0177 (8)0.0351 (9)0.0121 (7)0.0026 (7)0.0021 (7)
C440.0258 (8)0.0260 (9)0.0286 (8)0.0099 (7)0.0008 (6)0.0015 (7)
C450.0250 (8)0.0262 (10)0.0497 (11)0.0050 (7)0.0091 (7)0.0095 (8)
C460.0240 (8)0.0187 (9)0.0458 (11)0.0059 (7)0.0065 (7)0.0080 (7)
C510.0154 (7)0.0163 (7)0.0198 (7)0.0041 (5)0.0014 (5)0.0006 (5)
C520.0312 (8)0.0216 (8)0.0186 (7)0.0011 (7)0.0026 (6)0.0019 (6)
C610.0268 (8)0.0130 (7)0.0218 (7)0.0025 (6)0.0021 (6)0.0001 (6)
Geometric parameters (Å, º) top
S2—C21.6894 (15)C45—C461.389 (3)
O51—C511.2262 (19)C51—C521.512 (2)
N1—C21.365 (2)C4—H41.0000
N1—C61.3968 (19)C14—H141.0000
N3—C21.3287 (19)C15—H15A0.9800
N3—C41.4746 (19)C15—H15B0.9800
N1—H10.83 (2)C15—H15C0.9800
N3—H30.840 (19)C16—H16A0.9800
C4—C411.527 (2)C16—H16B0.9800
C4—C51.518 (2)C16—H16C0.9800
C5—C511.474 (2)C42—H420.9500
C5—C61.354 (2)C43—H430.9500
C6—C611.495 (2)C45—H450.9500
C14—C441.524 (2)C46—H460.9500
C14—C151.527 (3)C52—H52A0.9800
C14—C161.526 (3)C52—H52B0.9800
C41—C461.392 (2)C52—H52C0.9800
C41—C421.388 (2)C61—H61A0.9800
C42—C431.400 (3)C61—H61B0.9800
C43—C441.382 (2)C61—H61C0.9800
C44—C451.392 (3)
C2—N1—C6122.71 (13)C41—C4—H4108.00
C2—N3—C4122.78 (12)C15—C14—H14108.00
C6—N1—H1117.0 (14)C16—C14—H14108.00
C2—N1—H1118.5 (14)C44—C14—H14108.00
C2—N3—H3118.4 (13)C14—C15—H15A109.00
C4—N3—H3117.6 (14)C14—C15—H15B109.00
N1—C2—N3115.51 (13)C14—C15—H15C109.00
S2—C2—N3123.78 (12)H15A—C15—H15B109.00
S2—C2—N1120.71 (11)H15A—C15—H15C109.00
N3—C4—C41110.05 (12)H15B—C15—H15C109.00
C5—C4—C41113.87 (12)C14—C16—H16A109.00
N3—C4—C5107.72 (11)C14—C16—H16B109.00
C4—C5—C6117.84 (13)C14—C16—H16C109.00
C4—C5—C51118.63 (12)H16A—C16—H16B110.00
C6—C5—C51123.37 (13)H16A—C16—H16C109.00
N1—C6—C61112.76 (13)H16B—C16—H16C109.00
C5—C6—C61128.30 (14)C41—C42—H42120.00
N1—C6—C5118.89 (13)C43—C42—H42120.00
C15—C14—C16110.16 (17)C42—C43—H43119.00
C15—C14—C44110.36 (16)C44—C43—H43119.00
C16—C14—C44112.27 (16)C44—C45—H45119.00
C42—C41—C46118.48 (16)C46—C45—H45120.00
C4—C41—C42120.06 (14)C41—C46—H46120.00
C4—C41—C46121.43 (14)C45—C46—H46120.00
C41—C42—C43120.28 (16)C51—C52—H52A109.00
C42—C43—C44121.41 (16)C51—C52—H52B109.00
C14—C44—C43121.18 (16)C51—C52—H52C109.00
C14—C44—C45120.86 (16)H52A—C52—H52B109.00
C43—C44—C45117.95 (16)H52A—C52—H52C109.00
C44—C45—C46121.05 (17)H52B—C52—H52C109.00
C41—C46—C45120.78 (16)C6—C61—H61A109.00
O51—C51—C52120.17 (13)C6—C61—H61B109.00
C5—C51—C52117.29 (13)C6—C61—H61C109.00
O51—C51—C5122.53 (13)H61A—C61—H61B109.00
N3—C4—H4108.00H61A—C61—H61C109.00
C5—C4—H4108.00H61B—C61—H61C109.00
C6—N1—C2—S2163.66 (11)C51—C5—C6—C614.0 (2)
C6—N1—C2—N315.1 (2)C4—C5—C51—O51164.54 (13)
C2—N1—C6—C521.1 (2)C4—C5—C51—C5216.63 (19)
C2—N1—C6—C61161.20 (13)C6—C5—C51—O5120.2 (2)
C4—N3—C2—S2162.66 (11)C6—C5—C51—C52158.59 (14)
C4—N3—C2—N118.6 (2)C15—C14—C44—C43107.02 (19)
C2—N3—C4—C541.10 (18)C15—C14—C44—C4571.9 (2)
C2—N3—C4—C4183.58 (17)C16—C14—C44—C43129.67 (19)
N3—C4—C5—C632.96 (17)C16—C14—C44—C4551.4 (2)
N3—C4—C5—C51151.56 (12)C4—C41—C42—C43176.53 (15)
C41—C4—C5—C689.38 (16)C46—C41—C42—C431.7 (2)
C41—C4—C5—C5186.10 (15)C4—C41—C46—C45176.17 (16)
N3—C4—C41—C4292.42 (16)C42—C41—C46—C452.0 (3)
N3—C4—C41—C4685.75 (17)C41—C42—C43—C440.5 (3)
C5—C4—C41—C42146.53 (14)C42—C43—C44—C14176.54 (16)
C5—C4—C41—C4635.3 (2)C42—C43—C44—C452.4 (3)
C4—C5—C6—N15.98 (19)C14—C44—C45—C46176.88 (18)
C4—C5—C6—C61171.27 (13)C43—C44—C45—C462.1 (3)
C51—C5—C6—N1178.77 (13)C44—C45—C46—C410.2 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O51i0.83 (2)2.12 (2)2.9445 (17)174 (2)
N3—H3···S2ii0.840 (19)2.56 (2)3.3481 (13)156.9 (18)
C61—H61A···O510.982.222.9148 (19)127
C61—H61B···S2iii0.982.863.7145 (16)146
Symmetry codes: (i) x, y+1, z1/2; (ii) x, y, z; (iii) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC16H20N2OS
Mr288.41
Crystal system, space groupMonoclinic, C2/c
Temperature (K)123
a, b, c (Å)26.8413 (5), 9.5657 (2), 12.0764 (2)
β (°) 90.370 (2)
V3)3100.62 (10)
Z8
Radiation typeCu Kα
µ (mm1)1.83
Crystal size (mm)0.49 × 0.23 × 0.18
Data collection
DiffractometerOxford Diffraction Xcalibur Ruby Gemini
diffractometer
Absorption correctionMulti-scan
(CrysAlis PRO; Agilent, 2012)
Tmin, Tmax0.831, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
5607, 3042, 2776
Rint0.024
(sin θ/λ)max1)0.622
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.113, 1.05
No. of reflections3042
No. of parameters193
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.42, 0.39

Computer programs: CrysAlis PRO (Agilent, 2012), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O51i0.83 (2)2.12 (2)2.9445 (17)174 (2)
N3—H3···S2ii0.840 (19)2.56 (2)3.3481 (13)156.9 (18)
C61—H61A···O510.982.222.9148 (19)127
C61—H61B···S2iii0.982.863.7145 (16)146
Symmetry codes: (i) x, y+1, z1/2; (ii) x, y, z; (iii) x, y+1, z.
 

Acknowledgements

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

References

First citationAgilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.
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