反应详情

Sodium hydride (60% in oil, 220 mg, 5.5 mmol) was suspended in DMF (2 ml) and the suspension was stirred on a water bath. To the suspension was added dropwise a solution of 4,5,7-trifluoro-2-mercaptobenzothiazole (1.1 g, 5 mmol) in DMF (5 ml) under ice cooling and the mixture was stirred for 30 min. at room temperature and then cooled on a water bath. To the cooled mixture was added dropwise a solution of ethyl 5-bromopentanoate (1.05 g, 5 mmol) in DMF (3 ml) and the mixture was stirred for 2 hours at room temperature. The resultant mixture was diluted with water, then acidified with 7% hydrochloric acid and extracted with ethyl acetate. The organic layer was washed with an aqueous saturated saline solution, dried and then evaporated. The resulting residue was purified on a silica gel column to give 5-(4,5,7-trifluorobenzothiazol-2-ylthio)pentanoic acid ethyl ester (1.1 g, 64%) as an oil.

1. stirringthe mixture was stirred for 30 min. at room temperature
2. temperaturecooled on a water bath
3. stirringthe mixture was stirred for 2 hours at room temperature
4. extractionextracted with ethyl acetate
5. washThe organic layer was washed with an aqueous saturated saline solution
6. customdried
7. customevaporated
8. customThe resulting residue was purified on a silica gel column