Hydrochloric Acid → 1-[2-(3,4-dihydro-1(2H)-benzopyran-4-yl)ethyl]-4-(3,5-dimethoxyphenyl)piperazine dihydrochloride

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Reaction Steps

The procedure of Example 1 is followed, starting 4-(2-bromoethyl)-3,4-dihydro(2H)-benzopyran (2 g), 1-(3,5-dimethoxyphenyl)piperazine (1.84 g) and dry potassium carbonate (0.56 g), followed by potassium iodide (1.4 g) in 2-butanone (70 cc). The residue obtained is chromatographed on a column 4.4 cm in diameter, containing silica gel (100 g), using a dichloromethane-ethyl acetate mixture (50-50 by volume) as eluent and collecting 20-cc fractions. The fractions between 200 and 400 cc are concentrated to dryness. The oil obtained is taken up with ethanol (30 cc) and a 5N solution of hydrochloric acid in isopropanol (1.8 cc) is added. The crystals formed are filtered off and 1-[2-(3,4-dihydro-1(2H)-benzopyran-4-yl)ethyl]-4-(3,5-dimethoxyphenyl)piperazine dihydrochloride (1.9 g) is thus obtained in the form of a solid melting at 208° C.

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