Abstract The reaction of N, N′-bis (arylmethylidene) arylmethane diimines with thiourea under reflux in methanol was studied. The reaction gave a diastereomeric mixture of 4, 6- disubstituted 1, 3, 5-triazinane-2-thiones in good yields. Two diastereoisomers of 4, 6- diphenyl-1, 3, 5-triazinane-2-thione were detected in a solution of CDCl 3 by NMR analysis. According to the NMR studies, the cis-diastereoisomer undergoes a solvent-induced cis/ ...