反应详情

Sodium hydroxide (0.105 g; 2.63 mmole) was pulverized and dissolved in DMSO (8 ml). To 4 ml of this solution 2-[4-(tert-butoxycarbonylamino)phenyl]ethyl-4-methylbenzenesulfonate (described in Example 40a) (0.515 g; 1.316 mmole) and 2-ethoxy-3-(4-hydroxyphenyl)2-methyl propanoic acid ethyl ester (0.331 g; 1.316 mmole) were added and the mixture was stirred at room temperature over night. The remaining volume (4 ml) of the sodium hydroxide solution and water (1 ml) were added. A precipitate was formed which was dissolved by addition of tetrahydrofuran (1 ml). The mixture was allowed to stand over night and was then evaporated. The residue was redissolved in dichloromethane and water and the phases were separated. The water phase was extracted once more with dichloromethane, acidified with hydrochloric acid (1 M), extracted several times with ethyl acetate and diethyl ether. The organic phases were combined, dried with magnesium sulfate and evaporated. Purification of the crude product by flash chromatography and preparative HPLC gave 0.103 g (17.1% yield) of 3-[4-{2-(4[-tert-butoxycarbonylamino]phenyl)ethoxy}phenyl]-2-ethoxy-2-methyl-propanoic acid.

1. customA precipitate was formed which
2. waitto stand over night
3. customwas then evaporated
4. dissolutionThe residue was redissolved in dichloromethane
5. customwater and the phases were separated
6. extractionThe water phase was extracted once more with dichloromethane
7. extractionextracted several times with ethyl acetate and diethyl ether
8. dry with materialdried with magnesium sulfate
9. customevaporated
10. customPurification of the crude product by flash chromatography and preparative HPLC