Tricyclic derivative, its production and pharmaceutical composition used to produce anticancer effect in warm-blooded animal

PURPOSE: To provide a novel compound having an enzyme receptor tyrosine kinase inhibiting activity and being useful as an anticancer for the treatment of receptor tyrosine kinase sensitive cancers such as breast cancers, lung cancers and colon cancers. CONSTITUTION: There is provided a compound of formula I (wherein R 1 and R 2 are combined with each other to form a group such as -N=CH-NH- or -N=CH-O-, provided that the N atom is in the position 6 of the quinazoline ring; n is 1-3, and R 3 is H, a halogeno or the like) or a salt thereof (e.g. 3ethyl-8-(3'-methylanilino)-1,2-dihydro-3H-imidazo[4,5-g]quinazolin-2-one). This compound is obtained by reacting a quinazoline of formula II (wherein Z is a substitutable group) with an aniline of formula III desirably in the presence of an inert solvent such as THF. It is desirable that this reaction is performed at 20-80°C. COPYRIGHT: (C)1995,JPO