Methyl chloroformate → HCID 67356414, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-[5-(3,5-Dichloro-phenyl)-5-methyl-4,5-dihydro-isoxazol-3-yl]-2-methyl-benzoic acid tert-butyl ester (1.3 g) in dry tetrahydrofuran (15 ml) stirred under argon at −78° C., was added lithium hexamethyldisilazane (“LHMDS”) (1 M in hexane) (3.45 ml). The solution was stirred at −78° C. until deprotonation was completed as monitored by thin layer chromatography. Then, to this solution was added methyl chloroformate (0.465 ml) and the reaction mixture was stirred at −78° C. for 2 hours. The mixture was quenched with saturated ammonium chloride and then extracted with ethyl acetate. The combined organic extracts were dried over magnesium sulfate and concentrated. The residue was purified by chromatography on silica gel (eluent: heptane/diisopropylether 1:1) to give 3-(4-tert-butoxycarbonyl-3-methyl-phenyl)-5-(3,5-dichloro-phenyl)-5-methyl-5H-isoxazole-2-carboxylic acid methyl ester (472 mg) as a yellow foam.

Provenance & Evidence