Hydrochloric Acid → 3-(4-Bromophenyl)-1-dimethylamino-3-phenylthio-2-propene

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Reaction Steps

By using a method similar to that described in Example 35, but starting from 1-(4-bromophenyl)-3-dimethylamino-2-propen-1-one (10 g), phosphorus oxychloride (3.64 g), thiophenol (4.2 cc) and sodium cyanoborohydride (1.47 g), a residue is obtained which is taken up in chloroform. The solution is adjusted to pH 10 by adding a concentrated aqueous solution of sodium hydroxide. The organic phase is separated and then the aqueous phase is extracted with methylene chloride. The organic phases are collected, dried over sodium sulphate, filtered and then evaporated to dryness under reduced pressure (2.6 kPa) at 30° C. to give a residue which is dissolved in isopropanol (30 cc). A 3N ether solution (13 cc) of hydrochloric acid gas is added to the solution obtained. The white solid which precipitates is separated off by filtration and recrystallised twice from isopropanol (40 cc). In this way 3-(4-bromophenyl)-1-dimethylamino-3-phenylthio-2-propene (E) hydrochloride (4.8 g) is obtained in the form of white crystals melting at 187° C.

Provenance & Evidence