Hydrochloric Acid → HCID 59492824, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of an optically active form (33.3 g) of t-butyl[4-(2-fluoro-9-hydroxy-9-trifluoromethyl-9H-fluoren-4-yl)-pyrazol-1-yl]-acetate and paraformaldehyde (18.3 g) in dimethylformamide (100 ml) was added at room temperature a 1M solution (244 ml) of tetrabutylammonium fluoride in tetrahydrofuran, and the mixture was stirred at 90° C. for 4 hr. To the reaction mixture was added 1N hydrochloric acid (400 ml), and the mixture was extracted with ethyl acetate (200 ml). The separated aqueous layer was extracted twice with ethyl acetate (100 ml). The combined organic layer was successively washed once with 1N hydrochloric acid (100 ml), twice with brine (water/saturated brine=100 m1/10 ml) and once with saturated brine (100 ml), dried over anhydrous sodium sulfate and concentrated under reduced pressure. The obtained residue was azeotroped twice with toluene to give the title compound (28.3 g).

Provenance & Evidence