THE INFLUENCE OF SUBSTITUENTS IN 3-POSITION ON THE ACTIVITY OF CHROMAN-TYPE POTASSIUM CHANNEL ACTIVATORS

Swern oxidation of chromanol 1 led to ketone 3 with concomitant chlori nation of the adjacent 4-position. Using Leuckart conditions, chromano ne 2 was converted to enamine 5. - 4-Bromochromene-3-carbaldehyde 8, w hich was obtained by Vilsmeier-Arnold reaction from 7, turned out to b e a suitable intermediate for the insertion of the pyridone residue. 3 -Chloro derivatives 16 and 19 resulted on heating the mesylate or tosy late with LiCl in DMF, Bromination of chromene 20 led to 21. - All com pounds were tested for oral antihypertensive activity in spontaneously hypenensive rats with a dose of 1 mg/kg.