A new method based on the acid-catalyzed reaction of pyridoxal with polyfunctional phenols has been developed for the synthesis of potentially biologically active 1-aryl-6-methyl-1,3-dihydrofuro[3,4-c]pyridin-7-ols. Advantages of this method include a good yield of the target furopyridines and the use of readily available hydrochloric acid as a catalyst. The possibility of extending the proposed approach to nucleophiles other than phenols was demonstrated by the synthesis of the known biologically active compound 1-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-6-methyl-1,3-dihydrofuro[3,4-c]pyridin-7-ol hydrochloride (TM2002).
Key words
phenols - furans - pyridines - aldehydes - polycycles - heterocycles