Hydrochloric Acid → HCID 178437448, compound

Participants

Reaction Conditions

Reaction Steps

6-Amino-2-ethyl-5,7-dimethyl-3H-imidazo[4,5-b]-pyridine (0.85 g; preparable as in Example 10(b)) was dissolved with stirring in a mixture of concentrated hydrochloric acid (1.15 ml) and water (1.15 ml) and the resulting solution was cooled to 0° C. A solution of sodium nitrite (0.34 g) in water (1 ml) was added, dropwise, keeping the internal temperature below 5° C. The resulting solution was stirred at this temperature for 10 minutes and then added to a stirred solution of cuprous chloride (0.48 g) in concentrated hydrochloric acid (t.7 ml) keeping the temperature below 10° C. The mixture obtained was stirred at 70° C. for 2 hours and then cooled to ambient temperature. A precipitate was collected and washed with water (5 ml). Recrystallisation of this precipitate from methanol (7.5 ml) gave the intermediate compound 6-chloro-2-ethyl-5,7-dimethyl-3H-imidazo[4,5-b]pyridine hydrochloride (0.21 g; m.p. 284°-287° C. with decomposition). When left for 18 hours the reaction mixture yielded a further quantity of precipitate, which was collected by filtration and recrystallised from methanol to give a second crop (70 mg) of the intermediate compound identified above.

Provenance & Evidence