2-Amino-1,1,3-tricyanopropene in Heterocyclic Synthesis: Novel Synthesis of Thiopyran Pyridinethiones and Nicotinonitrile Derivatives

2-Amino-1,1,3-tricyano-3-bromopropene was obtained from bromination of malononitrile dimer, 2-amino-1,1,3-tricyanopropene with N-bromo-succinimide (NBS). The reactions of this bromo derivative with sodium hydrogen sulfide and thioglycollic acid afforded thiophene and thiopyran derivatives respectively. A novel synthesis of pyridinethione and nicotinonitrile derivatives by using 3-amino-4,4-dicyano-3-butenethioamide as starting material are reported and the synthetic potential of the method is described.