Dihydronaphtho £1, 2-b| pyrane derivative and its producing process and use

Pharmaceutical compounds of the formula in which n is 0, 1 or 2 and R is attached at any of the positions 7, 8, 9 or 10, and each R is halo, carboxy, trifluoromethyl, hydroxy, C1-4 alkyl, C1-4 alkoxy, C1-4 alkylthio, hydroxy-C1-4 alkyl, hydroxy-C1-4 alkoxy, nitrogen-containing heterocyclyl, nitro, trifluoromethoxy, -COOR where R is an ester group, -COR , -CONR R or -NR R where R and R are each hydrogen or C1-4 alkyl; R is phenyl, naphthyl or heteroaryl selected from thienyl, pyridyl, benzothienyl, quinolinyl, benzofuranyl or benzimidazolyl, said phenyl, naphthyl and heteroaryl groups being optionally substituted, or R is furanyl optionally substituted with C1-4 alkyl; R is nitrile, carboxy, -COOR where R is an ester group, or -CONR R where R and R are each hydrogen or C1-4 alkyl; and R is -NR R , -NR COR , -N(COR )2 or -N=CHOCH2R where R and R are each hydrogen or C1-4 alkyl optionally substituted with carboxy, -N=CH-NR R where R is hydrogen or C1-4 alkyl and R is C1-4 alkyl, optionally substituted phenyl or optionally substituted heteroaryl, where X is C2-4 alkylene, or -NHSO2R where R is C1-4 alkyl, trifluoromethyl or optionally substituted phenyl; and salts thereof.