反应详情

A mixture of 22.3 g of 1-carbethoxy-4-(5-chlorobenzimidazol-2-on-1-yl)-piperidine, 13 g of 50% strength sodium hydroxide solution and 90 ml of water was boiled under reflux for 24 hours. After the mixture had been cooled, the solution was stirred with 8.5 g of ammonium chloride for 30 minutes and extracted with chloroform, and the undissolved material was filtered off and discarded. The chloroform solution was dried and evaporated. The product crystallized, and has a melting point of 220° C.

1. temperatureunder reflux for 24 hours
2. temperatureAfter the mixture had been cooled
3. extractionextracted with chloroform
4. filtrationthe undissolved material was filtered off
5. dry with materialThe chloroform solution was dried
6. customevaporated
7. customThe product crystallized