3-Acetyl-1-(2,5-dimethylphenyl)thiourea

In the title compound, C11H14N2OS, the thioamide C=S and amide C=O bonds are anti to each other; the N—H bonds are also anti to each other. The molecular conformation is stabilized by an N—H⋯O hydrogen bond. In the crystal, the molecules are linked into inversion dimers by pairs of N—H⋯S hydrogen bonds.

In the title compound, C 11 H 14 N 2 OS, the thioamide C S and amide C O bonds are anti to each other; the N-H bonds are also anti to each other. The molecular conformation is stabilized by an N-HÁ Á ÁO hydrogen bond. In the crystal, the molecules are linked into inversion dimers by pairs of N-HÁ Á ÁS hydrogen bonds.
The conformation of the two N-H bonds are anti to each other. Furthermore, 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 syn to the ortho-methyl group, compared 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 Experimental 3-Acetyl-1-(2,5-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 2,5-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 by its infrared spectrum.
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
All H atoms bonded to C were positioned with idealized geometry (methyl H atoms allowed to rotate but not to tip) and were refined using a riding model with U iso (H) = 1.2 U eq (C) (1.5 for methyl H atoms) and with aromatic C-H = 0.93 Å and methyl C-H = 0.96 Å. The amino H atoms were refined isotropically with the N-H distances restrained to 0.86 (2)Å. To improve values of R1, wR2, and GOOF one bad reflection (-1 3 3) was omitted from the refinement.

3-Acetyl-1-(2,5-dimethylphenyl)thiourea
Crystal data 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.  (2) N2-H2N 0.849 (15) C7-S1 1.6692 (17)