Oxalic Acid → N-{1-[2-(3,4-Dihydro-2H-1-benzopyran-4-yl)ethyl]-4-piperidyl}-N-phenyl-4-fluorobenzamide

Participants

Reaction Steps

The procedure is as in Example 4, but starting with 4-(2-bromoethyl)-3,4-dihydro-2H-benzopyran (1.6 g), N-phenyl-N(4-piperidyl)-4-fluorobenzamide hydrochloride (2.21 g), dry potassium carbonate (1.8 g) and potassium iodide (0.8 g) in 2-butanone (50 cc). The oil obtained is taken up in the minimum amount of acetone and oxalic acid (0.6 g), dissolved in acetone, is added. The white precipitate formed is filtered off on sintered glass and then recrystallized in ethanol (50 cc). N-{1-[2-(3,4-Dihydro-2H-1-benzopyran-4-yl)ethyl]-4-piperidyl}-N-phenyl-4-fluorobenzamide acid oxalate (2.7 g) is thereby obtained in the form of a white solid, m.p. 161° C.

Provenance & Evidence