Pyranobenzoxadiazole derivatives

A compounds of the formula (I):

• ##STR39## wherein A represents OH or OC(O)CH.sub.3-n X.sub.n in which X represents fluorine atom, chlorine atom, bromine atom, a methyl group or a methoxy group and n represents 0 or an integer of 1 to 3, or A and B together represents a bond;
• B represents hydrogen atom or a bond together with A;
• when R.sup.1 represents hydrogen atom, R.sup.2 represents hydrogen atom, C(Z)CH.sub.3-n X.sub.n or C(Z)NHCH.sub.3-n X.sub.n in which Z represents oxygen atom or sulfur atom and X has the same meaning as defined above;
• when R.sup.1 does not represent hydrogen atom, R.sup.1 and R.sup.2 together represents (CH.sub.2).sub.m, (CH.sub.2).sub.m- C(Z), N(R.sup.3)(CH.sub.2).sub.2 C(Z), (CH.sub.2).sub.m-2 NHC(Z) or (CH.sub.2).sub.m-2 OC(Z) in which m represents an integer of 4 or 5, R.sup.3 represents hydrogen atom or a methyl group and Z has the same meaning as defined above, or pharmacological acceptable salts of the compounds which can form salts.