The reaction between carbon disulfide and some α-methylaminonitriles. The supposed isomerism of 4,4-dialkyl-5-imino-3-methylthiazolidine-2-thiones

The reaction of carbon disulfide with α-methylaminonitriles 1 yields 5-iminothiazolidine-2-thiones 3, which on prolonged reaction are converted to 5-methyliminothiazolidine-2-thiones 5 and 2,4-dithiohydantoins 9. A mechanism for this apparent methyl transfer is advanced. The yellow compounds obtained by prolonged reaction of the aminonitriles 1 (R1 = R2 = Me and R1 = Et, R2 = Me) are not isomers of the imines 3 (R1 = R2 = Me and R1 = Et, R2 = Me), but 2:1 complexes of these imines with the corresponding 2,4-dithiohydantoins 9 (R1 = R2 = Me and R1 = Et, R2 = Me).