3-Acetyl-1-(2,4-dimethylphenyl)thiourea

In the crystal structure of the title compound, C11H14N2OS, the two N—H bonds are anti to each other. There is an intramolecular N—H⋯O hydrogen bond generating an S(6) ring motif.In the crystal, molecules are linked via N—H⋯S hydrogen bonds with an R 2 2(8) motif and N—H⋯O hydrogen bonds with an R 2 2(12) motif into chains running along [1-10].

In the crystal structure of the title compound, C 11 H 14 N 2 OS, the two N-H bonds are anti to each other. There is an intramolecular N-HÁ Á ÁO hydrogen bond generating an S(6) ring motif.In the crystal, molecules are linked via N-HÁ Á ÁS hydrogen bonds with an R 2 2 (8) motif and N-HÁ Á ÁO hydrogen bonds with an R 2 2 (12) motif into chains running along [110].
The conformation of the two N-H bonds are anti to each other. The conformations of the amide C═S and the C═O are also anti to each other and both the bonds are anti to the adjacent N-H bonds, similar to the anti conformation observed in 3-acetyl-1-(2,3-dimethylphenyl)thiourea (I) (Kumar et al., 2012). The adjacent N-H bond is anti to the ortho-methyl group, similar to the anti conformation observed with respect to the ortho-and meta-methyl groups in the benzene ring of (I).
The side chain is oriented itself with respect to the phenyl ring with the C2-C1-N1-C7 and C6-C1-N1-C7 The NH hydrogen atom adjacent to the phenyl ring and the amide oxygen are involved in bifurcated hydrogen bonding, exhibiting the simultaneous intra-and inter-molecular hydrogen bonding. In the crystal structure, series of N-H···O and N-H···S intermolecular hydrogen bonds (Table 1) link the molecules into R 2 2 (8) and R 2 2 (12) networks (Fig.2).
Experimental 3-Acetyl-1-(2,4-dimethylphenyl)thiourea was synthesized by adding a solution of acetyl chloride (0.10 mol) in acetone (30 ml) dropwise to a suspension of ammonium thiocyanate (0.10 mol) in acetone (30 ml). The reaction mixture was refluxed for 30 min. After cooling to room temperature, a solution of 2,4-dimethylaniline (0.10 mol) in acetone (10 ml) was added and refluxed for 3 h. The reaction mixture was poured into acidified cold water. The precipitated title compound was recrystallized to constant melting point from acetonitrile. The purity of the compound was checked and characterized.
Prism like colourless single crystals used in X-ray diffraction studies were grown in acetonitrile solution by slow evaporation of the solvent at room temperature.

Refinement
H atoms bonded to C were positioned with idealized geometry using a riding model with aromatic C-H = 0.93 Å and methyl C-H = 0.96 Å. The coordinates of the amino H atoms were refined with the N-H distances restrained to 0.86 (2) Å. All H atoms were refined with isotropic displacement parameters set at 1.2 U eq (C-aromatic, N) and 1.5 U eq (Cmethyl) of the parent atom.  (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).  Molecular packing of the title compound with hydrogen bonding shown as dashed lines.

3-Acetyl-1-(2,4-dimethylphenyl)thiourea
Crystal data C 11 H 14 N 2 OS M r = 222.30 Triclinic, P1 Hall symbol: -P 1 a = 5.0510 (7)  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 F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.  (3)