Amino-acid derivatives and the preparation thereof

摘要

Novel amino acids of the general formula where (a) either one of R1 and R2 is hydrogen and the other is hydroxy or alkoxy, or (b) both R1 and R2 are hydroxy or alkoxy, R3 is H or alkyl, R4 is hydrogen, R5 is hydrogen, -COOR6 where R6 is H or alkyl, or R4 and R5 together with the carbon atom to which they are attached form a keto group or cyclic ketal group, n is 1 or 2 and Y is H, alkyl or aralkyl, are prepared by reductively condensing an appropriate b -phenethylamine with an appropriate cycloalkanone-2-acetic acid or ester by reacting the starting materials in an inert solvent medium and introducing gaseous hydrocarbon under pressure into the reaction mixture in the presence of a hydrogenation catalyst. The compounds are intermediates in the preparation of novel indolizine and indolizinium compounds.