Methanol → 7-[5-(3,5-Dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-benzo[1,2,5]thiadiazole-4-carboxylic acid methyl ester

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Reaction Steps

Triethylamine (7.8 ml) and methanol (72 ml) were added at ambient temperature to a solution of 4-bromo-7-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-benzo[1,2,5]thiadiazole (7.96 g) (Example I6) in N,N-dimethylformamide (72 ml). [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) (“PdCl2(dppf)”) (654 mg) was added and the reaction mixture was stirred in a pressure reactor in an atmosphere of carbon monoxide (3 bar) at 87° C. for 16 hours. The reaction mixture was cooled to ambient temperature, filtered through a plug of Celite® and concentrated. The residue was purified by column chromatography (heptane/ethyl acetate) to give 7-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-benzo[1,2,5]thiadiazole-4-carboxylic acid methyl ester (4.01 g) as an orange oil. 1H-NMR (CDCl3, 400 MHz): 8.43-7.57 (m, 5H), 4.66 (d, 1H), 4.27 (d, 1H), 4.09 (s, 3H) ppm.

Provenance & Evidence