Benzopyrans and use thereof in treating vascular diseases

A compound of the formula I ##STR15## wherein the group OR represents hydroxy;

• lower alkoxy which is unsubstituted or substituted by hydroxy, lower alkoxy, amino, lower alkylamino, di-lower alkylamino, carboxy or lower alkoxycarbonyl;
• or lower alkanoyloxy;
• one of the radicals R' and R" represents hydroxy, lower alkoxy, lower alkanoyloxy or lower alkyl and the other one is hydrogen;
• or the groups OR and R' together form a bivalent methylenedioxy radical which is unsubstituted or substituted by lower alkyl and/or phenyl, and R" is hydrogen;
• or the groups OR and R" together form a bivalent methylenedioxy radical which is unsubstituted or substituted by lower alkyl and/or phenyl, and R' is hydrogen;
• and the ring B is unsubstituted or substituted by lower alkyl, phenyl-lower alkyl, diphenyl-lower alkyl, phenyl, lower alkanoyloxy, halogen, amino, lower alkylamino, di-lower alkylamino, phenylamino, lower alkanoylamino, benzoylamino;
• lower alkylsulfonylamino, phenylsulfonylmino;
• lower alkanoyl, benzoyl, carboxy, lower alkoxycarbonyl, carbamoyl, N-lower alkylcarbamoyl, N,N-dilower alkylcarbamoyl, cyano, ureido, N-lower alkylureido, lower alkylsulfonyl;
• phenylsulfonyl;
• lower alkyl which is substituted by hydroxy, lower alkoxy, amino, lower alkylamino, di-lower alkylamino, halogen, carboxy or lower alkoxycarbonyl;
• lower alkoxy which is substituted by hydroxy, lower alkoxy, amino, lower alkylamino, di-lower alkylamino, halogen, carboxy or lower alkoxycarbonyl;
• C.sub.3 -C.sub.7 -alkoxy;
• and/or bivalent methylenedioxy;
• or wherein the ring B is monosubstituted by hydroxy, methoxy or ethoxy, provided that R' is other than hydroxy, methoxy or ethoxy, if the group OR represents hydroxy, methoxy or ethoxy;
• or wherein the ring B is disubstituted by methoxy and lower alkoxy, provided in case of 2',4'-dimethoxy substitution that R' and R" are other than methoxy, if the group OR represents methoxy;
• with the proviso that the ring B must be substituted, if R' is hydroxy and the group OR represents hydroxy or methoxy;
• it being possible for all phenyl groups mentioned as such or in composed radicals to be unsubstituted or substituted by lower alkyl, lower alkoxy, halogen, hydroxy and/or nitro;
• or a salt thereof.