Fromm’s methylphenyldithiodimethylketuret

The ’keturet’ obtained by reacting 1-methyl-1-phenyldithiobiuret with acetone is shown to be 6,6-dimethyl-2-methylanilino-5,6-dihydro-4H-1,3,5-thiadiazine-4-thione, C12H15N3S2. The molecule contains a six-membered thiadiazine ring with a distorted half-chair conformation, rather than a previously proposed four-membered ring structure. Molecular dimensions are normal, and the molecules (two per asymmetric unit) are linked by two N-H ... S hydrogen bonds, one fairly strong [H ... S 2.39 (3) Angstrom] and one weaker [H ... S 2.65 (4) Angstrom].