Acridone derivatives and preparation of 8-hydroxy-imidazoacridinone derivatives

摘要

A compound of formula (I): wherein R 1 and R 2 are alkyl groups of 1 to 4 carbon atoms and n is from 2 to 5, is prepared by reacting a 1-chloro-7-(protected hydroxy)-4-nitroacridin-9(10 H )-one of formula (IV-P) wherein A is a hydroxy-protecting group removable by reduction, with an * small Greek omega *-(dialkylamino)alkylamine of formula NH 2 -(CH 2 ) n NR 1 R 2 in which n, R 1 and R 2 are as defined above, to produce a 7-(protected hydroxy)-4-nitro-1- * small Greek omega *-(dialkylamino)alkylaminoacridin-9(10 H )-one (III-P), reducing the compound III-P at a temperature of from 15 to 50{C with a hydrogen gas or with formate ions, in the presence of a palladium catalyst and formic acid, removing substantially all the residual palladium and heating the remaining reaction mixture to effect cyclisation to the corresponding compound of formula (I). If desired, after removal of the palladium the novel intermediate 7-hydroxy-4-N-formyl-1- * small Greek omega *-(dialkylamino)alkylaminoacridin-9(10 H )-one can be isolated and subsequently cyclised by heating. Such compounds have antineoplastic activity.