反应详情

A mixture of 1.2 g (4.67 mmol) of N-(tert-butoxycarbonyl)-3-cyclopentyl-L-alanine, 540 mg (5 mmol) of benzyl alcohol, 675 mg (5 mmol) of 1-hydroxybenzotriazole, 1.152 g (6 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.031 g (0.25 mmol) of 4-dimethylaminopyridine was stirred in 20 ml of dichloromethane for 1 hour and then a further 610 mg (5 mmol) of 4-dimethylaminopyridine were added. After 4 hours the solution was extracted with 2M hydrochloric acid and saturated sodium bicarbonate solution, dried over anhydrous magnesium sulphate and evaporated. The oil obtained was chromatographed on silica gel using ethyl acetate/ petrol (1:6) for the elution to give 1.55 g of N-(tert-butoxycarbonyl)-3-cyclopentyl-L-alanine benzyl ester as a colourless oil; MS: m/e 348 [M+H].

1. extractionAfter 4 hours the solution was extracted with 2M hydrochloric acid and saturated sodium bicarbonate solution
2. dry with materialdried over anhydrous magnesium sulphate
3. customevaporated
4. customThe oil obtained
5. customwas chromatographed on silica gel
6. washfor the elution