Hydrochloric Acid → 3-hydroxy-2-hydroxymethyl-2-[4-(9-hydroxy-2-methyl-9-trifluoromethyl-9H-fluoren-4-yl)-pyrazol-1-yl]-propionic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of an optically active form (17.8 g) of t-butyl [4-(9-hydroxy-2-methyl-9-trifluoromethyl-9H-fluoren-4-yl)-pyrazol-1-yl]-acetate and paraformaldehyde (12.0 g) in dimethylformamide (60 ml) was added at room temperature a 1M solution (120 ml) of tetrabutylammonium fluoride in tetrahydrofuran, and the mixture was stirred at 95° C. for 3 hr. To the reaction mixture were added 1N hydrochloric acid (180 ml) and water (90 ml), and the mixture was extracted with ethyl acetate (180 ml). The separated aqueous layer was extracted twice with ethyl acetate (90 ml). The combined organic layer was successively washed once with 1N hydrochloric acid (90 ml), twice with water (90 ml) and once with saturated brine (90 ml), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to give the title compound (15.5 g).

Provenance & Evidence