N-(4'-chloro-2'-fluoro-5'-isopropyloxyphenyl)-3-(trifluoromethyl)glutaramic acid → N-(4'-chloro-2'-fluoro-5'-isopropyloxyphenyl)-5-hydroxy-3-(trifluoromethyl)pentanamide

Participants

Reaction Steps

To a solution of N-(4'-chloro-2'-fluoro-5'-isopropyloxyphenyl)-3-(trifluoromethyl)glutaramic acid (4.32 g, 11.4 mmol) in 20 ml of tetrahydrofuran, (freshly distilled from sodium/benzophenone) was slowly added 10M borane-methyl sulfide complex (1.18 ml) via syringe. The temperature was maintained at 10°-20° C. with an ice bath while vigorous bubbling was evident. The mixture was allowed to warm slowly to room temperature and stirred 150 hrs while kept under nitrogen, heated to 55° C. for 6 hours, then cooled to room temperature and allowed to stand for 16 hours. The flask was cooled in an ice/water bath, then 7 ml of methanol (MeOH) were added slowly via addition funnel. The reaction mixture became too thick to continue stirring. It was allowed to warm slowly to room temperature, when the stir bar was again able to stir the mixture. The MeOH and THF were removed in vacuo (20-50 Torr) and the residue was flash chromatographed (2"×7" column, 3:1 hexanes/ethyl acetate, 75 ml fractions). Fractions 18-45 were combined and the solvent was removed in vacuo. The residue was dried in the vacuum oven at 50° C. to yield 1.66 g (39% yield) of the pentanamide as a nearly colorless oil.

Provenance & Evidence