反应详情

To a solution of 1-[4-(4-fluoro-phenoxy) benzenesulfonylamino]-cyclopentanecarboxylic acid (10.22 g, 27 mmole) in 100 mL methylene chloride at -78□ C. was condensed 40 mL of isobutylene. Concentrated sulfuric acid (0.3 mL) was added and the mixture allowed to warm to ambient temperature and stirred for 22 hours. The mixture was then washed with 3×50 mL 2N NaOH and the organic layer dried over magnesium sulfate and evaporated to give 11.17 g (95%) of 1-[4-(4-fluoro-phenoxy)-benzenesulfonylamino]-cyclopentanecarboxylic acid tert-butyl ester. 1H NMR (CDCl3) □ 7.74-7.77 (m, 2H), 6.85-7.13 (m, 6H), 4.95 (s, 1H), 1.92-2.02 (m, 2H), 1.78-1.88 (m, 2H), 1.50-1.65 (m, 4H), 1.35 (s, 9H).

1. washThe mixture was then washed with 3×50 mL 2N NaOH
2. dry with materialthe organic layer dried over magnesium sulfate
3. customevaporated