4-substituted benzopyran and related compounds

A method for treating ischemia comprising administering to a mammalian specie in need thereof a therapeutically effective amount of a pharmaceutical composition comprising a compound of the formula ##STR20## or pharmaceutically acceptable salts thereof wherein a, b and d are all carbon atoms or one of a, b and d is a nitrogen atom or --N(O)-- and the others are carbon atoms;

• A is a single bond, --CH.sub.2 --, --O--, --S-- or --N(R)-- where R is hydrogen, alkyl, haloalkyl, aryl, arylalkyl, cycloalkyl or (cycloalkyl)alkyl;
• R.sup.1 is hydrogen, alkyl, halo, haloalkyl, nitro or cyano:
• R.sup.2 is hydrogen, alkyl or halo;
• R.sup.3 is --COR, --CO-amino, --CO-substituted amino, --NRCOOR--*, --NRCO-amino or --NRCO-substituted amino (where R--* is the same or different R, as defined above);
• R.sup.4 is hydrogen, alkyl, alkenyl, aryl, aryl, alkyl, cycloalkyl or (cycloalkyl)alkyl;
• or R.sup.3 and R.sup.4 together with the carbon and nitrogen atoms to which they are attached, form a fused imidazole ring, unsubstituted or substituted at an available carbon atom of the imidazole portion with one or more substituents selected from hydrogen, alkyl, cyano, --COR, --COOR, --CO-amino, --CO-substituted amino, --NRCOOR--*, --NRCO-amino or --NRCO-substituted amino;
• R.sup.5 is hydrogen, hydroxy or --OC(O)R;
• R.sup.6 and R.sup.7 are each independently hydrogen, alkyl or arylalkyl, or R.sup.6 and R.sup.7 taken together with the carbon atom to which they are attached form a 5- to 7-membered carbocyclic ring;
• R.sup.8 is hydrogen, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl, arylalkyl, (cycloalkyl)alkyl, --CN, --NO.sub.2, --COR, --COOR, --CONHR, --CONR.sup.5, --CF.sub.3, S-alkyl, --SOalkyl, --SO.sub.2 alkyl, ##STR21## halogen, amino, substituted amino, --O-alkyl, --OCF.sub.3, --OCH.sub.2 CF.sub.3, --OCOalkyl, --OCONRalkyl, --NRCOalkyl, --NRCOOalkyl or-NRCONR.sup.5 ;
• R.sup.9 is hydrogen, alkyl, hydroxy, --O---alkyl, amino, substituted amino, --NHCOR, --CN or --NO.sub.2 ;
• and
• n is an integer of 1 to 3;
• provided that when a, b and d are carbon atoms, R.sup.3 is --NRCOOR*-and R.sup.4 is hydrogen, that one of R.sup.1 or R.sup.2 is other than hydrogen;
• and a pharmaceutically acceptable carrier.