Verfahren zur Herstellung von neuen Aminosäuren

The invention comprises compounds of the formula (wherein R1 is hydrogen or alkyl; R2 and R3\t are each C1-5 alkyl; R4 and R5 are each hydrogen or C1-6 alkanoyl; X is hydrogen, hydroxyl, alkanoyloxy, halogen, alkyl or trifluoromethyl; and n is 1 or 2, being 1 when X is hydroxyl or alkanoyloxy; with the provisos that R4O groups are not attached in both the 3- and 5-positions, and that when R4 is hydrogen, R5 is also hydrogen) and non-toxic acid-addition salts thereof; the preparation of the compounds wherein R1, R4 and R5 are hydrogen by reaction of a ketone of the formula with ammonium carbonate and a water soluble cyanide to form a hydantoin, decomposition of this with barium hydroxide to form the corresponding methoxyphenyl-amino-acid and demethylation of this with a hydrohalic acid, or by reaction of the said ketone with ammonium chloride and a water-soluble cyanide to form directly an a - amino - a ,b - dialkyl - b - methoxy-phenyl-alanine and demethylation of this; followed, when required, by the preparation of the compounds wherein R1 is alkyl by esterification of the acids with an alkanol in the presence of an acid catalyst, and/or, when required, the preparation of the compounds wherein R4 and R5 are alkanoyl by acylation of the acids or the esters with an excess of an alkanoic acid halide or anhydride in the presence of an organic base, or, when required, the preparation of the compounds wherein R4 is acyl and R5 is hydrogen by acylation of the acids or the esters with an alkanoic acid halide or anhydride under Schotten-Baumann conditions. Examples are given. Ketones of the second general formula above are prepared by either of the following processes (A) and (B) The phenylalanine derivatives of the invention, or their salts, which are stated to be anti-hypertensives, may be made up into pharmaceutical compositions with suitable carriers, and, if desired, other anti-hypertensives. Oral (e.g. tablets) and parenteral forms are mentioned. Specification 988,002 is referred to.ALSO:Compounds of the formula (wherein R1 is hydrogen or alkyl; R2 and R3 are each C1- 5 alkyl; R4 and R5 are each hydrogen or C1- 6 alkanoyl, X is hydrogen, hydroxyl, alkanoyloxy, halogen, alkyl or trifluoromethyl; and n is 1 or 2, being 1 when X is hydroxyl or alkanoyloxy; with the provisos that R4O groups are not attached in both the 3- and 5-positions, and that when R4 is hy