Potassium Iodide → 5-Cyano-7-iodo-1-phenylbenzimidazole

Participants

Reaction Conditions

Reaction Steps

A suspension of 7-Amino-5-cyano-1-phenylbenzimidazole (12.5 g, 53.4 mmol) in hydrochloric acid (90 ml, 25% w/v) was diazotised with a solution of sodium nitrite (3.7 g, 53.4 mmol) in water (20 ml). The resultant mixture was stirred for 30 min at 0° C. whereafter a solution of potassium iodide (14.2 g, 85.5 mmol) in water (40 ml) was added dropwise. Stirring was continued for 10 min at 0° C., and then the temperature was raised to 80° C. for 30 min. After cooling, aqueous sodium sulphite (1M) was added and the resultant mixture was extracted with dichloromethane. Column chromatographic work-up of the dried and concentrated organic extract afforded the title product (6.5 g, 35%)

Provenance & Evidence