Reactive intermediates in the reaction of hydrazinecarbothioamides with 2-(bis(methylthio)methylene)malononitrile and ethyl 2-cyano-3,3-bis(methylthio)acrylate

The reaction of N-substituted hydrazinecarbothioamides with both 2-(bis(methylthio)methylene)malononitrile and ethyl 2-cyano-3,3-bis(methylthio)acrylate afforded various heterocyclic rings such as 5-amino-4-cyano-3-(methylthio)-N-phenyl-1H-pyrazole-1-carbothioamide, 5-amino-3-(methylthio)-1H-pyrazole-4-carbonitrile, 4-substituted-3-(substituted amino)-1H-1,2,4-triazole-5(4H)-thione, ethyl 5-amino-3-(methylthio)-1-(substituted carbamothioyl)-1H-pyrazole-4-carboxylate, and (Z)-ethyl 2-cyano-2-(5-(substituted amino)-1,3,4-thiadiazol-2(3H)-ylidene)acetate. However, under gentle heating, the reaction of the same starting substances behaved differently. The structure of the obtained products was fully characterized using different spectral techniques including infrared (IR), nuclear magnetic resonance (NMR), and mass spectrometry (MS) together with elemental analyses as well as single-crystal X-ray diffraction analysis.