Process for the synthesis of (±) 2-Amino-N-[2,(2,5-dimethoxy phenyl)-2-hydroxyethyl] acetamide monohydrochloride

A process for synthesising (±)2-amino-N-[2-(2,5-dimethoxyphenyl)-2-hydroxyethyl]acetamide monohydrochloride which comprises the steps of:

• (a) reacting 1-(2,5-dimethoxyphenyl)-2-bromoethanone with hexamine in tetrahydrofuran water solvent system to produce 1-(2′,5′-dimethoxyphenyl)-2-amino ethanone;
• (b) acylating said 1-(2′,5′-dimethoxyphenyl)-2-aminoethanone with haloacetylchloride and sodium acetate in acetone water solvent medium to produce 2-chloro-N-(β-oxo-2,5-dimethoxyphenyl)acetamide;
• (c) subjecting said acetamide obtained in step (b) to nucleophilic azidation with sodium azide in acetone medium;
• (d) subjecting said 2-azido-N-(β-oxo-2,5,-dimethoxyphenyl)acetamide to selective reduction of the carbonyl group by treating with sodium borohydride and subsequently reducing the azide group with stannous chloride to obtain (±)2-amino-N-[-2-(2,5-dimethoxyphenyl)-2-hydroxyethyl]acetamide which is converted into the corresponding monohydrochloride by treatment with concentrated hydrochloric acid and recovered from the reaction mixture in a known manner.