Sodium Hydroxide → trans-2-(4-Bromobenzoyl)cyclopentanecarboxylic acid

Participants

Reaction Steps

A solution of NaOH (128.2 g, 3.2 mol) in 700 mL water was added to a solution of cis-2-(4-bromo-benzoyl)-cyclopentanecarboxylic acid methyl ester (166.3 g, 534.3 mmol) in MeOH (700 mL). The reaction mixture was stirred at rt overnight. NMR analysis showed that little starting material remained. After ca. 1 L solvent was removed by rotary evaporation, the mixture was diluted with 1 L water. Conc. HCl was slowly added with stirring at <15° C., to adjust the acidity to pH <6. A precipitate formed, and stirring was continued for 1 h. The solid precipitate was filtered, and rinsed with water. The dried filter cake was dissolved in 1 L EtOAc, and dried over Na2SO4. Removal of solvent and drying in vacuo afforded the desired product (131 g, 83%). 1H NMR (CDCl3) δ 7.83 (d, 2H), 7.60 (d, 2H), 4.05 (m, 1H), 3.50 (m, 1H), 2.20 (m, 2H), 2.00 (m, 1H), 1.78 (m, 3H).

Provenance & Evidence