反应详情

A solution of N-(3,5-dimethylbenzoyl)-3-[4-(5-isoxazolyl)-phenyl]-alanine ethyl ester (3.8 g) and methyliodide (1.8 ml) in dry N,N-dimethylformamide (40 ml) is cooled in an ice bath and sodium hydride (60% in oil, 390 mg) is added in portions. The mixture is allowed to warm to room temperature during 5 hours, then poured into water, extracted with ethyl acetate, the organic phase washed with water, and with brine, dried and evaporated. Flash chromatography of the residue on silica gel (hexanelethyl acetate 3:1) gives pure N-(3,5-di methylbenzoyl)-N-methyl-3-[4-5-isoxazolyl)-phenyl]-alanine ethyl ester. N-(3,5-dimethylbenzoyl)-N-methyl-3-[4-(5-isoxazolyl)-phenyl]-alanine ethyl ester (44 mg) is treated with lithium hydroxide monohydrate (5 mg) in methanol (0.5 ml), tetrahydrofurane (0.25 ml), and water (0.25 ml) for 3 hours at room temperature. The mixture is then partitioned between water and ether, the water phase acidified with 1N hydrochloric acid, and subsequently extracted with ethyl acetate. The ethyl acetate phase is washed with brine, dried, and evaporated to give N-(3,5-dimethylbenzoyl)-N-methyl-3-[4-(5-isoxazolyl)-phenyl]-alanine.

1. customThe mixture is then partitioned between water and ether
2. extractionsubsequently extracted with ethyl acetate
3. washThe ethyl acetate phase is washed with brine
4. customdried
5. customevaporated