反应详情

1.26 g (2.5 mmole) of the methyl ester from Example 8 was dissolved in 25 ml of methanol in a single neck 100 ml round bottom flask. Next a solution of 202 mg (5 mmole) of sodium hydroxide in 10 ml water was added. The resulting mixture was stirred with the aid of a magnetic stirring bar for 2 hours at room temperature. The methanol was removed by rotary evaporation and the residue was acidified with dilute hydrochloric acid to pH 2. The acidified solution was extracted three times with 30 ml portions of ethyl acetate. The combined ethyl acetate extracts were dried over anhydrous magnesium sulfate, filtered and the ethyl acetate removed by rotoevaporation to furnish 1.16 g (95%) of the title compound, mp 101°-102°. Calc: C, 71.87; H, 8.32; Found: C, 71.71; H, 8.31.

1. customThe methanol was removed by rotary evaporation
2. extractionThe acidified solution was extracted three times with 30 ml portions of ethyl acetate
3. dry with materialThe combined ethyl acetate extracts were dried over anhydrous magnesium sulfate
4. filtrationfiltered
5. customthe ethyl acetate removed by rotoevaporation