Synthesis of new pyrrolo[1,2-d][1,2,4]triazines and thiazolo[3,4-d][1,2,4]triazines as immunostimulating agents.

Four pyrrolo[1,2-d][1,2,4]triazines and four thiazolo[3,4-d][1,2,4]triazines were synthesized from trans-4-hydroxy-L-proline and L-thiaproline, respectively. The synthetic route involved formation of hydrazides followed by cyclization with orthoesters. The proliferative response to human lymphocyte mitogen (phytohemagglutinin) revealed significant immunostimulant activity for all test drugs. Furthermore, some triazine derivatives were effective to activate production of free oxygen radical by phagocytes in response to stimulation by opsonized zymosan.