Pyrimidopyrimidine derivatives, processes for producing them, pharmaceutical compositions containing them and their use as anti-allergic agents.

摘要

Pyrimidopyrimidine derivatives having the general formula (I):
<Chemistry id="chema01" num="0001"><Image id="ia01" he="32" wi="52" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>wherein R<Sub>1</Sub> represents an alkyl group; R<Sub>2</Sub> represents an alkyl or phenyl group; R<Sub>3</Sub> represents a hydrogen atom or an alkyl or lower alkylamino group; and R<Sub>4</Sub> represents a hydrogen atom or an alkyl, halogenated lower alkyl, phenyl, amino or lower alkylamino group; and pharmaceutically acceptable salts thereof have anti-allergic properties. Various processes for preparing these pyrimidopyrimidine derivatives are disclosed.