Water → 4-[5-(3,5-Dichloro-phenyl)-2-methyl-5-trifluoromethyl-2,5-dihydro-isoxazol-3-yl]-2-methyl-benzoic acid

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Reaction Steps

0.27 g of 4-[5-(3,5-Dichloro-phenyl)-2-methyl-5-trifluoromethyl-2,5-dihydro-isoxazol-3-yl]-2-methyl-benzoic acid ethyl ester (VIIIa) was stirred in a mixture of 5 ml of methanol, 5 ml of THF and 1 ml of water. To this solution 0.2 g KOH was added and the mixture was stirred for 5 days at ambient temperature. The solvents were then evaporated, the residue was diluted with water and acidified with 1N HCl. The solid that precipitated was isolated by filtration and dried to give 0.240 g (95%,) of 4-[5-(3,5-Dichloro-phenyl)-2-methyl-5-trifluoromethyl-2,5-dihydro-isoxazol-3-yl]-2-methyl-benzoic acid (IIa) as a pale solid. 1H-NMR (CDCl3, δ in ppm): 8.05 (d, 1H), 7.26-7.44 (m, 5H), 5.46 (s, 1H), 3.00 (s, 3H), 2.65 (s, 3H).

Provenance & Evidence