Hydrochloric Acid → 5-(2,5-difluorophenyl)-3,4-dihydro-2H-pyrrole

Participants

Reaction Conditions

Reaction Steps

In step 6A-2, concentrated hydrochloric acid (23 mL, 260 mmol) was added to a solution of tert-butyl 2-(2,5-difluorophenyl)-2-hydroxypyrrolidine-1-carboxylate (6-3) (15.6 g, 52 mmol) in methanol. The reaction mixture was heated to 70° C. while stirring and was then stirred at 70° C. for 6 hours. The reaction mixture was cooled to room temperature and neutralized with a 7.5 M solution of sodium hydroxide (35 mL, 263 mmol). The methanol was removed and the resulting slurry was reconstituted with ethyl acetate (250 mL). The organic layer was washed with brine (3×150 mL), and then dried with sodium sulfate. The ethyl acetate was then removed to yield 5-(2,5-difluorophenyl)-3,4-dihydro-2H-pyrrole (6-4) as a light yellow oil. m/z=182.2 [M+1].

Provenance & Evidence