反应详情

To N,N-diisopropylamine (2.6 mL, 18.4 mmol) in dry THF (40 mL) under dry nitrogen and at 0° C. was added n-BuLi (2.5 M, 7.35 mL, 18.3 mmol) dropwise and the reaction was stirred at rt for 20 min. The reaction mixture was again cooled to 0° C. and 3-(2-bromophenyl)-propionic acid (1.9 g, 8.29 mmol, dissolved in dry THF, 40 mL) was added dropwise via cannula and then warmed to rt and stirred for 15 min. The reaction mixture was again cooled to 0° C. and 1-iodo-2-methyl propane (1.5 mL, 13.26 mmol) was added dropwise. The reaction was then warmed to rt and stirred overnight. Aqueous 10% HCl was added carefully followed by brine and the product was extracted with EtOAc (3×), dried over Na2SO4, concentrated in vacuo, and purified by flash chromatography over silica gel (EtOAc/Hex/AcOH, 4/6/0.5%) to afford 2-(2-bromobenzyl)-4-methylpentanoic acid.

1. temperatureThe reaction mixture was again cooled to 0° C.
2. temperaturewarmed to rt
3. stirringstirred for 15 min
4. temperatureThe reaction mixture was again cooled to 0° C.
5. temperatureThe reaction was then warmed to rt
6. stirringstirred overnight
7. extractionthe product was extracted with EtOAc (3×)
8. dry with materialdried over Na2SO4
9. concentrationconcentrated in vacuo
10. custompurified by flash chromatography over silica gel (EtOAc/Hex/AcOH, 4/6/0.5%)