The Influence of Substituents in 3‐Position on the Activity of Chroman‐Type Potassium Channel Activators

Abstract

Swern oxidation of chromanol 1 led to ketone 3 with concomitant chlorination of the adjacent 4-position. Using Leuckart conditions, chromanone 2 was converted to enamine 5.--4-Bromochromene-3-carbaldehyde 8, which was obtained by Vilsmeier-Arnold reaction from 7, turned out to be a suitable intermediate for the insertion of the pyridone residue. 3-Chloro derivatives 16 and 19 resulted on heating the mesylate or tosylate with LiCl in DMF. Bromination of chromene 20 led to 21.--All compounds were tested for oral antihypertensive activity in spontaneously hypertensive rats with a dose of 1 mg/kg.