反应详情

A mixture of α-methyl-4'-(hydroxy)[1,1'-biphenyl]-4-acetic acid (22.0 g, 90.8 mmol) in ethanol (500 mL) and concentrated sulfuric acid (5.0 mL) is refluxed for 30 hours. The solution is concentrated under reduced pressure, is diluted with water (300 mL) and is extracted with ethyl acetate (3×300 mL). The combined ethyl acetate extract is washed with water (400 mL) and brine (400 mL), dried over MgSO4 and is concentrated under reduced pressure to give 20 g of crude product. Purification of this material by column chromatography (25% ethyl acetate in hexane) followed by crystallization from ethyl acetate and hexane gives 18.0 g (73.5%) of crystalline product, m.p. 124°-125° C., MS(CI+ m/z): 271[M+H]+.

1. temperatureis refluxed for 30 hours
2. concentrationThe solution is concentrated under reduced pressure
3. additionis diluted with water (300 mL)
4. extractionis extracted with ethyl acetate (3×300 mL)
5. extractionThe combined ethyl acetate extract
6. washis washed with water (400 mL) and brine (400 mL)
7. dry with materialdried over MgSO4
8. concentrationis concentrated under reduced pressure
9. customto give 20 g of crude product
10. customPurification of this material by column chromatography (25% ethyl acetate in hexane)
11. customfollowed by crystallization from ethyl acetate and hexane