6 - hydrazono pyrido (2,1) kinazolin - 11 million jemte seen for their framstellning

摘要

Compounds of the general formula IMAGE (wherein R, R1 and R2, which may be the same or different, each represents a hydrogen or halogen atom or a nitro, carboxy, cyano, C1-4 alkoxy, C1-4 alkyl, amino, or hydroxy group or an alkoxycarbonyl group in which the alkoxy contains 1 to 4 carbon atoms; or R and R1 together represent a methylenedioxy group, and R2 represents a hydrogen atom; R3 represents a hydrogen atom or a C1-4 alkyl group; R4 represents a hydrogen atom or a C1-4 alkyl group, a naphthyl or pyridyl group or a phenyl group substituted by 1 to 3 substituents, which may be the same or different, selected from halogen, C1-4 alkyl, C1-4 alkoxy, phenoxy, hydroxy, nitro, amino, cyano, carboxy, alkoxycarbonyl in which the alkoxy moiety contains 1 to 4 carbon atoms, alkanoyl in which the alkyl moiety contains 1 to 4 carbon atoms, methylenedioxy, trifluoromethyl, phenyl and mono- or di-alkylamino in which the alkyl moiety contains 1 to 4 carbon atoms; and each dotted line represents an optional further bond and the salts, optical and geometrical isomers and tautomers thereof are intermediates in the preparation of Rutaecarpine and the analogues thereof. The compounds of formula I may be prepared by reaction of a pyrido[2,1-b]quinazolin-11-one with a diazonium salt or with hydrazine or a derivative thereof.