Stereochemistry of the reaction of primary amenies and hydrazine tives with activated alkynes

The reaction of methyl 3-[4-substituted phenyl]-propynoates I a, b and 3-[4-chlorophenyl]-1-phenyl-2-propyn-1-one II with 2-pyridylmethylamine III in methanol gave the corresponding E- and Z-enamine derivatives, respectively. The reaction of II with 4-amino-5-mercapto-3-methyl-1, 2, 4-triazole IV yielded a mixture of E, Z-enamine and imine derivatives. PMR and IR spectra confirmed the configuration assigned to the enamine products. Treatment of II with 2-hydrazinobenzothiazole V gave a mixture of the hydrazone and pyrazole derivatives