Chromanyl substituted indole potassium channel openers

A compound of the formula ##STR11## wherein X is --O--;

• R.sub.1 and R.sub.7 are independently selected from H, alkyl, haloalkyl, cycloalkyl, arylalkyl, CN, NO.sub.2, COR, COOR, CONHR, CONR.sub.2, halo wherein R in each of the above groups can be hydrogen, alkyl, haloalkyl, aryl, arylalkyl, cycloalkyl, or (cycloalkyl)alkyl where at least one of R.sub.1 or D.sub.7 is H:
• R.sub.2 is hydrogen, hydroxy, ##STR12## R.sub.3 and R.sub.4 are each independently selected from hydrogen, alkyl or arylalkyl, or, R.sub.3 and R.sub.4 taken together with the carbon atom to which they are attached form a 5- to 7-membered ring;
• R.sub.5 is hydrogen, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl, arylalkyl, (cycloalkyl)alkyl, --CN, --NO.sub.2, --COR, --COOR, --CONHR, --CONR.sub.2, --CF.sub.3, S-alkyl, --SOalkyl, --SO.sub.2 alkyl, ##STR13## halogen, amino, substituted amino, O-alkyl, OCF.sub.3, OCH.sub.2 CF.sub.3, --OCOalkyl, --OCONRalkyl, --NRCOalkyl and NRCOOalkyl, NRCONR.sub.2 wherein R in each of the above groups can be hydrogen, alkyl haloalkyl, aryl, arylalkyl, cycloalkyl, or (cycloalkyl)alkyl;
• R.sub.6 is selected from H, alkyl, OH, O-alkyl, amino, substituted amino, NHCOR, CN, and NO.sub.2 wherein R can be hydrogen, alkyl, haloalkyl, aryl, arylalkyl, cycloalkyl, or (cycloalkyl)alkyl;
• R.sub.8 is H, alkyl, haloalkyl, cycloalkyl, O--R, CN, NO.sub.2, CF.sub.3, halo, S-alkyl, COR, COOR, NRCOalkyl, OCOalkyl wherein R in each of the above groups can be hydrogen, alkyl, haloalkyl, aryl, arylalkyl, cycloalkyl, or (cycloalkyl)alkyl;
• m is O;
• and
• n is 1, 2 or 3.