N-(Diphenyl­carbamothio­yl)-3-methyl­benzamide

The synthesis of the title compound, C(21)H(18)N(2)OS, involves the reaction of 3-methyl­benzoyl chloride with potassium thio­cyanate in dry acetone followed by condensation of the 3-methyl­benzoyl isothio­cyanate with diphenyl­amine. The carbonyl [C—O = 1.215 (2) Å] and thio­carbonyl [C—S = 1.6721 (17) Å] distances indicate that these correspond to double bonds. The short C—N bonds at the center of the mol­ecule reveal the effects of resonance in this part of the mol­ecule. The conformation of the mol­ecule with respect to the thio­carbonyl and carbonyl groups is twisted. The 3-methyl­phenyl and two phenyl rings are also twisted, with dihedral angles of 75.67 (9) and 14.91 (9)°. The phenyl rings are rotated out of the mean plane of the N—C—S—N atoms by 66.87 (8) and 78.40 (9)°. Pairs of mol­ecules are linked into centrosymmetric dimers via inter­molecular N—H⋯S inter­actions and a C—H⋯O link also occurs. The dimers are stacked along the a axis.