5 a b c d e f g h I j k l R 4-Cl 4-Cl 4-Cl 4-Cl 4-H 4-H 4-H 4-H 4-CH3 4-CH3 4-CH3 4-CH3 R1 4-CH3 4-Cl 4-H 4-NO2 4-Cl 4-H 4-CH3 4-NO2 4-Cl 4-H 4-CH3 4-NO2

Reagents and Conditions: (a) Triethyl orthoformate, toluene, reflux; (b) R-PhCONHNH2, toluene, AcOH, reflux, 12 h; (c) MeOH, NaOH, rt; (d) Substituted acid hydrazides, POCl3, reflux, 6 h.

Scheme 1: Synthetic path way of preparation of 1,3,4-oxadiazole and 1,2,4-triazolethienopyrimidine derivatives.