Process for the preparation of indolo[2',3';3,4]pyrido[2,1-b]quinazolin-5-one derivatives

摘要

The invention relates to a process for the preparation of indolo[2',3';3,4]pyrido[2,1-b]quinazolin-1-one derivatives of the formula I <IMAGE> in which, if R<1>, R<2>, R<3> and R<4> denote hydrogen, R is methoxy, benzyloxy, hydroxyl or methoxycarbonyl, if R, R<1> and R<4> denote hydrogen and R<3> denotes methoxy, R<2> is hydrogen, hydroxyl, benzyloxy or methoxy, if R, R<2>, R<3> and R<4> denote hydrogen, R<1> is hydroxyl or methoxy, if R denotes methoxy and R<1> and R<4> denote hydrogen, R<2> and R<3> are methoxy, if R, R<1> and R<4> denote hydrogen, R<2> and R<3> together form methylenedioxy, if R, R<1>, R<3> and R<4> denote hydrogen, R<2> is methoxy, or R, R<1>, R<2>, R<3> and R<4> denote hydrogen, or acid addition salts thereof, by heating compounds of the formula II <IMAGE> in which R, R<1>, R<2>, R<3> and R<4> have the abovementioned meaning, or their acid addition salts, in the presence of an organic, inorganic or Lewis acid. The compounds of the formula I exhibit a diuretic effect, and they affect blood pressure and respiration.