反应详情

Water (200 ml) was added to a solution of 3-{4-[2-(4-aminophenyl)ethoxy]phenyl}-(S)-2-ethoxypropanoic acid ethyl ester hydro chloride (described in Example 41b) (15 g; 42 mmole) in tetrahydrofuran (100 ml). Lithium hydroxide (3.4 g; 84 mmole) dissolved in a small amount of water was added while stirring and then the reaction mixture was stirred at room temperature over night. Tetrahydrofuran was evaporated and the remaining residue was extracted twice with ethyl acetate. The water phase was acidified with hydrochloric acid (2 M) and extracted with ethyl acetate. The organic phase was dried with magnesium sulfate. Evaporation gave 6.4 g of 3-{4-[2-(4-aminophenyl)ethoxy]phenyl}-(S)-2-ethoxypropanoic acid hydro chloride. The acidic water phase, from above, was neutralized with sodium hydroxide to pH5 and extracted with dichloromethane. The organic phase was dried with magnesium sulfate and evaporated. This procedure gave 1.4 g more of the desired product. The total yield of 3-{4-[2-(4-aminophenyl)ethoxy]phenyl}-(S)-2-ethoxypropanoic acid hydro chloride was 7.8 g (50.8%).

1. additionwas added
2. stirringthe reaction mixture was stirred at room temperature over night
3. customTetrahydrofuran was evaporated
4. extractionthe remaining residue was extracted twice with ethyl acetate
5. extractionextracted with ethyl acetate
6. dry with materialThe organic phase was dried with magnesium sulfate
7. customEvaporation