Alfa Chemicals Italiana S.p.a.

Alfa Chemicals Italiana S.r.l.

Barbara Galbiati

Vincenzo Cannata

Tiziano Ferrario

Angelo Spreafico

The process for the production of form I of anhydrous terazosin monohydrochloride consists of heating terazosin suspended in a mixture made by methanol and a solvent selected from C.sub.2 to C.sub.6, straight or branched alcohols, esters of C.sub.1 -C.sub.8 aliphatic carboxylic acids with straight or branched C.sub.1 to C.sub.8 alcohols, C.sub.3 to C.sub.8 aliphatic ketones, C.sub.4 to C.sub.8 straight branched or cyclic aliphatic ethers, aliphatic amides and aliphatic nitriles with a methanol solution of hydrochloric acid.

Process for the production of the form I of the anhydrous terazosin

The process for the production of the form I of the terazosin monohydrochloride anhydrous consists of treating at the boiling temperature terazosin monohydrochloride dihydrate with a mixture of methanol and a solvent selected from C.sub.2 -C.sub.6 straight or branched alcohols, the esters of the C.sub. -C.sub.8 carboxylic aliphatic acids with C.sub.1 -C.sub.8 straight or branched alcohols, C.sub.3 to C.sub.8 aliphatic ketones, C.sub.4 to C.sub.8 straight, branched or cyclic aliphatic ethers, aliphatic amides and the aliphatic nitriles.

Process for the production of the form I of the terazosin

A process for manufacturing 1-(3-trifluoromethyl)phenyl-propan-2-one intermediate in the synthesis of the anorexic drug fenfluramine consists of reacting the diazonium salt of 3-trifluoromethylaniline with isopropenyl acetate in a polar solvent in the presence of a catalytic amount of a cuprous salt and, optionally, of a base and purifying the crude product through the bisulfite complex or distillation under vacuum.

Process for manufacturing 1-(3-trifluoromethyl)-phenyl-propan-2-one

Process for the production of the isomers (R) and (S)-.alpha.-methyl-3-(trifluoromethyl)benzeneethanamine, the second being useful as intermediate in the synthesis of the anorexic drug dexfenfluramine (INN), which comprises carrying out a stereospecific reductive amination of 1-(3-trifluoromethyl)phenyl-2-propanone with (R) or (S)-.alpha.-methylbenzylamine under a hydrogen atmosphere in the presence of a catalyst and debenzylating the resulting diastereoisomer (R),(R) or (S),(S)-N-(1-phenylethyl)-.alpha.-methyl-3-(trifluoromethyl)benzeneethanam ine by treatment with hydrogen and a catalyst.

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Milan, Italy

Barbara Galbiati