Structure of 2-amino-4-thiazolinone

It was shown by the methods of IR and NMR spectroscopy that 2-amino-4-thiazolinone (pseudothiohydantoin) exists in an amino form in the crystalline state and in solutions in dimethyl sulfoxide, water, and trifluoroacetic acid, and in this amino form all the nitrogen-carbon bonds are partially double. In dimethyl sulfoxide and trifluoroacetic acid there is an autoassociation with the formation of dimers. Inhibited rotation of the amino group around the exocyclic nitrogen-carbon bond was detected. The results of a calculation of the IR spectrum of 2-amino-4-thiazolinone according to the force-field method agrees with the experimental data.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1066–1070, August, 1984.