反应详情

To a solution of LDA in THF/n-heptane/ethylbenzene (1.8 M, 17 mL) at 0° C. is added a solution of 2-(3-bromo-phenyl)-propionic acid [3 g, 13.9 mmol, Intermediate (69)] in THF (5 mL) dropwise during 15 minutes. Stir for 1 hour, followed by addition of methyl iodide (4.93 g, 34.8 mmol) in THF (5 mL) dropwise during 10 min. The reaction mixture is stirred for 15 hours, quenched with 2N hydrochloric acid, concentrated in vacuo, and diluted with ether (150 mL). The ether layer is washed with 2N hydrochloric acid, extracted three times with 2N sodium hydroxide (50 mL), Combined sodium hydroxide layers are acidified with 6 N hydrochloric acid to pH=1 and extracted three times with ether (75 mL). Combined organic layers are washed with brine, dried over sodium sulfate and concentrated to obtain 2-(3-bromo-phenyl)-2-methyl-propionic acid as a solid (3.08 g, 91% yield), which is used without further purification. LC/MS: 243 (M+H)

1. stirringThe reaction mixture is stirred for 15 hours
2. customquenched with 2N hydrochloric acid
3. concentrationconcentrated in vacuo
4. additiondiluted with ether (150 mL)
5. washThe ether layer is washed with 2N hydrochloric acid
6. extractionextracted three times with 2N sodium hydroxide (50 mL)
7. extractionextracted three times with ether (75 mL)
8. washCombined organic layers are washed with brine
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated