Hydrochloric Acid → 2-[(2-Chlorophenyl)thio]-1H-imidazole

Participants

Reaction Steps

To a solution of 5.6 g (29.3 mmoles) of the product from Example 32 in 50 ml of 3N hydrochloric acid and 50 ml of glacial acetic acid (cooled in an ice bath), was added dropwise over 20 minutes, a solution of 2.0 g (29.3 mmoles) of sodium nitrite in 8 ml of water. After stirring for 10 minutes, the mixture was added to a cold solution of 8.7 g (80 mmoles) cuprous chloride in 80 ml of 6N hydrochloric acid. After stirring at room temperature for 5 hours, the mixture was concentrated and the residue made alkaline with ammonium hydroxide. The product was extracted with dichloromethane which was washed with saturated sodium chloride, dried and concentrated. The residue was dissolved in hot dichloromethane and filtered through silica gel using dichloromethane/ethyl acetate (1:1 by volume) as the eluent. The fractions containing the product were concentrated to give 4.9 g (79%) of the product which was crystallized from dichloromethane to give colorless rods, mp 138°-141° C.

Provenance & Evidence