Studies on Fungicides. XXV. Addition Reaction of Dithiocarbamates to Fumaronitrile, Bis (alkylthio) maleonitrile, 2, 3-Dicyano-5, 6-dihydro-1, 4-dithiin and 4, 5-Dicyano-2-oxo-1, 4-dithiole

Abstract

5-Cyanomethyl-2-thioxo-4-aminothiazolines (II) were prepared by the addition reaction of dithiocarbamates to fumaronitrile. In the reactions of bis (methylthio) maleonitrile (IXa), bis (benzylthio) maleonitrile (IXb), 2, 3-dicyano-5, 6-dihydro-1, 4-dithiin (IXc) and 4, 5-dicyano-2-oxo-1, 4-dithiole (IXd) with dithiocarbamates were obtained 5, 5'-bi-2-thioxo-4-aminothiazolines (X). The 4-amino groups of II and X were found to be labile and were hydrolyzed when heated with mineral acids to give 5-cyanomethyl-2-thioxo-4-thiazolidones (III) and 5, 5'-bi-2-thioxo-4-thiazolidones (XII), respectively. X was also found to be converted to Δ^{5, 5'}-bi-2-thioxo-4-iminothiazolidine (XI) by autoxidation in the presence of catalytic amount of triethylamine. 4-Oxo-4'-imino-Δ^{5, 5'}-bi-2-thioxo-thiazolidine (XVI) was prepared by the addition reaction of N-benzyldithiocarbamate to 5-cyanomethylidene-2-thioxo-4-thiazolidone (XIV). XI and XIV gave Δ^{5, 5'}-bi-2-thioxo-4-thiazolidones (XIII) on hydrolysis with mineral acids.