GB360266A - Manufacture of trialkoxy-derivatives of phenylethylamine - Google Patents

Abstract

3 : 4 : 5-Trialkoxyphenylethylamines, in which at least one alkoxy group contains more than one carbon atom, are prepared by catalytically reducing the corresponding 3 : 4 : 5-trialkoxynitrostyrenes. An example is given of the production of 3 : 4 : 5-triethoxyphenylethylamine by treating 3 : 4 : 5-triethoxynitrostyrene in alcohol solution with hydrogen in the presence of palladious chloride at 15 DEG C. The preparation of the samples is described in the Specification, in which connection it is stated that the treatment with hydrogen of 4-n-butoxy-3 : 5-dimethoxynitrostyrene in glacial acetic acid solution at ordinary temperature in the presence of palladious chloride, colloidal platinum or palladium, chloroplatinic acid or platinum black yields 4-n-butoxy-3 : 5-dimethoxyphenylethylamine.ALSO:3 : 4 : 5-Trialkoxy-phenylethylamines, in which at least one alkoxy group contains more than one carbon atom, are prepared by reducing the corresponding 3 : 4 : 5-trialkoxynitrostyrenes. The reduction may be effected chemically, catalytically or by electrolysis. The 3 : 4 : 5-trialkoxynitrostyrenes are obtained by converting 3 : 4 : 5-trialkoxybenzoic acids by way of their halides into the aldehydes and condensing the latter with nitromethane. According to the example, 3 : 4 : 5-triethoxybenzoic acid is heated with thionyl chloride and the resulting acid chloride treated with hydrogen in the presence of a barium sulphate-palladium catalyst to give triethoxybenzaldehyde; nitromethane is then added with cooling and the triethoxynitrostyrene formed is reduced with hydrogen in the presence of palladious chloride to the corresponding phenylethylamine. The Specification includes the following description of the preparation of the samples:--(1) the sodium salt of syringaic acid is heated with n-butyl bromide and the resulting 4-n-butoxy-3 : 5-dimethoxybenzoic acid converted with thionyl chloride into the acid chloride, which is then reduced with hydrogen and palladium to 4-n-butoxy-3 : 5-dimethoxybenzaldehyde; with nitromethane the latter gives 4-n-butoxy-3 : 5-dimethoxynitrostyrene which by treatment with hydrogen in the presence of palladious chloride, colloidal palladium, chloroplatinic acid, colloidal platinum or platinum black yields 4-n-butoxy-3 : 5-dimethoxyphenylethylamine; (2) in a similar manner, 4-benzyloxy-3 : 5-dimethoxyphenylethylamine is obtained from syringaic acid, the final reduction however being performed in two stages, first with zinc dust and glacial acetic acid to form 4-benzyloxy-3 : 5-dimethoxy-1-phenylacetaldoxime and then with sodium amalgam in alcoholic acetic acid to produce 4-benzyloxy-3 : 5-dimethoxyphenylethylamine.