Potassium tert-butoxide → 4-(7-Trifluoromethyl-benzo[d]isoxazol-3-yl)-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a room temperature mixture of 4-[(2-fluoro-3-trifluoromethyl-phenyl)-hydroxyimino-methyl]-piperidine-1-carboxylic acid tert-butyl ester (1.40 g, 3.59 mmol) in THF (20 mL) under nitrogen was added potassium tert-butoxide (3.60 mL of a 1M THF solution, 3.60 mmol) in one portion and the reaction heated at 60° C. for 1.5 h. After standing at room temperature overnight, the solvent was removed and the residue diluted with ethyl acetate (60 mL). The organics were washed with water (30 mL) and brine (30 mL) successively, dried over magnesium sulfate, filtered, and concentrated to give an amber solid. The crude product was chromatographed on silica using 40% ethyl acetate/heptane as eluent to afford 0.97 g (73%) of the desired product as a white solid, mp: 111-113° C.

Provenance & Evidence