反应详情

A solution of the ester from Step 1 (22.5 g) in 118 mL 1N LiOH, 120 mL THF, and 65 mL MeOH was heated at 60° C. for 2 hours. The mixture was cooled, poured onto 1N HCl, and extracted with EtOAc (3×). After washing the organic phase twice with brine, the solution was dried (MgSo4) and evaporated. The residue was swished with ether/hexane 1:2 to give the title compound as a solid; m.p. 196.5°-198° C.

1. temperatureThe mixture was cooled
2. extractionextracted with EtOAc (3×)
3. washAfter washing the organic phase twice with brine
4. customthe solution was dried (MgSo4)
5. customevaporated