Synthesis of N-Mannich bases from 5-((4-methylpiperazin-1-yl)methyl)-1,3,4-oxadiazole-2-thiol

Methyl (4-methylpiperazin-1-yl)acetate (2) were synthesized by the condensation of compound (1) with ethyl bromoacetate in basic media. aThe synthesis of acid hydrazide derivatives (3) was brought about as a result of the reaction between a compound (2) and hydrazine hydrate. In the absence of basic conditions, the reaction of 2-(4-methylpiperazin-1-yl)acetohydrazide (3) with carbon disulfide resulted in the formation of 5-((4-methylpiperazin-1-yl)methyl)-1,3,4-oxadiazole-2-thiol (4). aThe reactions of (4) with different primary and secondary amines in the presence of formaldehyde led to the formation of the corresponding Mannich bases (5a-f).