Alpha-amino-hydroxyphenylacetic acids prepn. - by cheap two-stage process from hydroxyphenylglyoxylic acids via oximes

摘要

Alpha-Amino-hydrocyphenylacetic acid inters. for semi-synthetic penicilline are prepd. in high yield by (a) conversion of glyoxylic acids of formula into their oximes of formula and (b) reduction of the oximes III to give the required acids of formula X = H, Cl. Stage (a) is conventional; stage (b) reduction is by alkali metals amalgams, alumino- and borohydrides, SnCl2, Sn, Fe or Zn with strong acids, catalytic hydrogenation etc.