4-Aminobenzoic Acid → 4,4'-(1,3,4-Oxadiazole-2,5-diyl)dianiline

Participants

Reaction Steps

60 g (0.46 mole) of hydrazine sulphate was dissolved in 700 ml of oleum with 20% SO3. 137 g (1.0 mol) p-aminobenzoic acid was added at room temperature. The mixture was stirred for 2.5 hours at a temperature of 70° C. to 75° C. and then poured onto 10 liters of ice and neutralized with a concentrated sodium hydroxide solution. The resulting precipitate was filtered off, washed with water, and again filtered off. The yield was 91 g of impure product. This impure product was recrystallized in ethanol. After partial evaporation of the resulting liquid, 73.5 g of pure 2,5-bis-(p-aminophenyl)-1,3,4-oxadiazole were obtained.

Provenance & Evidence