Abstract: Novel benzologs or pyrazolo-quinazoline derivatives of the formula (I) ##STR1## wherein X and Y are independently selected from oxygen, sulphur and imino and wherein ring (C) is a pyrazole ring fused to ring (B) via one of the three ortho positions or sides of ring (B); the fused pyrazole ring (C) is either in the 4,3- or the 3,4-arrangement; and tautomers of formula (I) compounds; when X is not oxygen, i.e. stands for sulphur or imino, Y may stand for a covalent bond that links the hydrogen directly to the carbon atom in position 2.Two methods for producing the novel formula (I) compounds are disclosed. The first or indazole method starts from a precursor having a benzene moiety (ring B) and a pyrazolo moiety (ring C) fused therewith, i.e. the indazole structure; ring (B) carries two vicinal substituents for forming the pyrimidine moiety or ring (A) by cyclization. The second or quinazoline method starts from a precursor having the pyrimidine moiety (A) and the benzene moiety (B) fused therewith, i.e.