Triethylamine → 2-(3-Chlorophenyl)-N-[4-(dimethylamino)phenyl]-3H-imidazo [4,5-b]pyridine-3-acetamide hydrochloride

Participants

Reaction Steps

Under a nitrogen atmosphere, oxalyl chloride (2.8 ml, 0.032 mole) was added dropwise (slowly) to a stirred and chilled solution of 2-(3-chlorophenyl)-3H-imidazo[4,5-b]pyridine-3-acetic acid (8.0 g, 0.028 mole) in anhydrous dimethylformamide (100 ml). The reaction was heated at 55°-60° C. for 3 hrs, cooled to room temperature, and added dropwise to a stirred and chilled (5°-10° C.) suspension of N,N-dimethyl-p-phenylenediamine dihydrochloride (6.7 g, 0.032 mole) and triethylamine (12.9 g, 0.128 mole) in anhydrous dimethylformamide (200 ml). The reaction was stirred at room temperature over the weekend, filtered, and poured into ice water (600 ml). The mixture was filtered and the filter cake recrystallized from ethanol giving 6.6 g (58%). The solid was converted to the hydrochloride salt in isopropyl alcohol and concentrated hydrochloric acid to give 6.6 g of a white granular solid, mp. 229°-231° C. with decomposition.

Provenance & Evidence