HETEROTRICYCLIC DERIVATIVES, PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM

摘要

Heterotricyclic derivatives of formula (I) wherein R<1> is hydrogen, lower alkyl, lower alkoxy, lower alkylthio, halogen, nitro, amino or protected amino, R<2> is hydroxy, protected hydroxy, halogen, amino or protected amino, R<3> is hydrogen or an organic group, R<4> is hydrogen or lower alkyl, R<8> is hydrogen or lower alkyl, and -Z- is -O- or a group of formula (II) (in which n is 0, 1 or 2), and pharmaceutically acceptable salts thereof which are useful as a medicament.