Sodium Hydroxide → 1-(4-Bromo-3-methylisoxazol-5-yl)cyclopropane-1-carboxylic acid

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Reaction Conditions

Reaction Steps

To a solution of ethyl 1-(4-bromo-3-methylisoxazol-5-yl)cyclopropane-carboxylate (11.8 g, 43.0 mmol) in THF (60 mL) was added aqueous NaOH (86 mL, 86 mmol, 1 M). The dark brown bi-phasic reaction mixture was vigorously stirred and heated to 45° C. until consumption of SM (3-4 h) was detected by LC-MS and TLC analysis. After 4 h, the homogeneous mixture was cooled to room temperature and diluted with hexanes. The organic phase was separated and the aqueous phase (pH˜14) was acidified with aqueous 1 N HCl (pH 1) (˜100 mL). The product crystallizes upon acidification of the aqueous layer. After vigorously stirring for 30 min, the solids were filtered, washed with cold (0° C.) water (3×50 mL), and dried to give white crystals. The product 1-(4-bromo-3-methylisoxazol-5-yl)cyclopropanecarboxylic acid (10.0 g, 40.6 mmol, 94% yield) was isolated as white crystals. LC/MS m/z 246 [M+H]+.

Provenance & Evidence