Studies on o-[2,6-dichlorophenyl-1-amino] phenyl acetic acid. I. Synthesis, antiinflammatory, analgesic and ulcerogenic activities of some new amino acid conjugates.

o-[2,6-Dichlorophenyl-1-amino]phenyl acetic acid (diclofenac) (I) reacted with some amino acid esters, namely glycine, L-valine, L-diiodotyrosine and L-tryptophan through the active ester to give the corresponding o-[2,6-dichlorophenyl-1-amino]benzyl carboxy-N-amino acid ester of the type (IIa-d), respectively, which were hydrolysed in alkaline medium to yield the free amino acids (IIIa-d). Condensation of the latter compounds with hydrazine hydrate gave the corresponding acid hydrazides (IVa-d), which in turn were reacted with trimethoxybenzaldehyde to give the corresponding Schiff's bases (Va-d), respectively. The antiinflammatory, ulcerogenic and analgesic activities of the obtained compounds were also investigated.