Synthesis of water-soluble lithium, sodium, potassium, and cesium salts of (E)-2-[4-methoxy(3,4-dimethoxy)-benzylideneamino]-2-alkyl(aralkyl)acetic acids

A convenient method of preparative synthesis of water-soluble lithium, sodium, potassium, and cesium salts of (E)-2-[4-methoxy(3,4-dimethoxy)benzylideneamino]-2-alkyl(aralkyl)acetic acids via reaction of anisic or veratric aldehyde with natural amino acids (glycine, L-valine, L-leucine, L-isoleucine or Ltryptophan) in the presence of lithium hydride or carbonates of sodium, potassium, or cesium in boiling methanol was developed.