PYRIMIDOPYRIMIDINE COMPOUNDS

摘要

A range of dipyridamole analogues useful for inhibiting transport of nucleosides or purines across cell membranes, thereby to potentiate the activity of various cytotoxic antitumour drugs, is diclosed. These analogues comprise compounds having general structural formula (I) or pharmaceutically acceptable salts thereof; wherein R1 is chloro and R3 is diethanolamino, or R1 and R3 are identical and are selected from allyl, halo, diethanolamino, solketalo and a group having the formula: -O-Rz or -NHRz, Rz being selected from alkyl, hydroxyalkyl, alkoxyalkyl, dialkoxyalkyl and 2-oxo-alkyl wherein the or each alkyl and/or alkoxy moiety has less than six carbon atoms, and R2 and R4 are identical and are selected from piperidino, N-tetrahydroisoquinolyl, and a benzylamino group having structural formula (II) wherein R5 is H, or an optionally substituted alkyl or benzyl group, and R6 and R7 represent H or optional substituents in the aromatic nucleus selected from halo, alkyl, alkoxy, hydroxy, trifluoromethyl, azido, cyano, nitro, carboxyl, carboxylic ester, amino or a substituted amino NRxRy where Rx and Ry each represent hydrogen or alkyl, subject to the provisos that (a) if R1 and R3 are both chloro or diethanolamino, R2 and R4 are not both benzylamino, i.e. R2 and R4 do not correspond to structure II with R5, R6 and R7 each being hydrogen, and (b) if R2 and R4 are both piperidino, R1 and R3 are not both chloro, diethanolamino, solketalo or (2,3-dimethoxy)propoxy.