2,4-Dichlorobenzoic Acid → 2,5-bis(2,4-dichlorophenyl)-1,3,4-oxadiazole

Participants

Reaction Conditions

Reaction Steps

A mixture was prepared by slowly adding 10 grams (g) of hydrazine hydrate to 400 g of vigorously stirring polyphosphoric acid at ~50° C. To this mixture was added 76 g (0.4 mole) of 2,4-dichlorobenzoic acid. A slurry developed and it was stirred at 125° C (+5°) for 5 hours. The reaction products were cooled slightly and poured into ~1.5 liter (1) of cold water. The solid which precipitated was recovered by filtration, washed with water, dried and recrystallized from chlorobenzene to give 54 g (75% of theoretical) of the desired 2,5-bis(2,4-dichlorophenyl)-1,3,4-oxadiazole.

Provenance & Evidence