Hydrazides (30-58) were synthesized by one pot conventionalmethod24 Benzoic acid or its derivative (10 mmol) was dissolvedin ethanol (20 mL). Sulfuric acid (3 N, 2 mL) was added and thereaction contents were refluxed for six hours. The reaction wasmonitored with TLC. After the completion of the reaction, the reactionmixture was neutralized by adding solid NaHCO3, and filteredto remove excess of NaHCO3. In the neutralized reaction mixture which contains ethyl ester, hydrazine monohydrate (1.5 mL,3 mmol) was added and refluxed for 3-6 h to complete the reaction.Ethanol and unreacted hydrazine were removed by distillationupto 1/3 volume. The reaction contents were cooled, filteredand recrystallized from methanol to obtain the desired hydrazidecrystals (see Supporting information).
