The attack of cyanide ion on primary and secondary aminoethyl thiosulfates yields 2-amino- A*-thiazolines. 2-Aminoethyl 2-aminoethanethiolsulfonate and 2-aminoethyl 2- aminoethanethiolsulfinate on treatment with cyanide also yield 2-amino-A2-thiazoline (I). The mass spectra of I, three isomeric methyl-2-amino-A~-thiazolines, 2-imino-3- amidinothiazolidine, and 2-amino-5, 6-dihydro-4H-lJ3-thiazine, made from thiosulfates by ...