Diisobutylaluminumhydride → {5-[5-(3,5-Dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophen-2-yl}-methanol

Participants

Reaction Steps

Diisobutylaluminium hydride (DIBAL-H, 28.4 ml, 1M in Toluene) is added to a solution of 5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid ethyl ester (6.42 g) in diethyl ether (120 ml) under nitrogen at −5° C. After 15 min at −5° C., the cold bad is removed. After 3 hours at room temperature, the reaction mixture is diluted with ethyl acetate and is quenched with a saturated solution of NaHCO3. The organic phase is separated and the aqueous phase is extracted once with ethyl acetate. The combined organic phases are extracted with a saturated solution of NaHCO3 and with a saturated aqueous solution of NaCl, dried over Na2SO4 and concentrated in vacuo. The crude product is purified on a semi-preparative HPLC to yield {5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophen-2-yl}-methanol (4.63 g) as a light yellow foam. MS (HPLC/MS): 410 (MH+). Retention time: 1.90 min.

Provenance & Evidence