Patent ID: 8835446

Claim:
A quinazoline derivative represented by the following general formula [1] or a pharmaceutically acceptable salt thereof: wherein R 1 represents hydrogen or alkyl; R 2 represents hydrogen, alkoxy, tetrahydropyranyl, phenyl, cycloalkyl, (cycloalkyl)alkyl or alkyl, wherein the alkoxy, tetrahydropyranyl, phenyl, cycloalkyl, (cycloalkyl)alkyl, and alkyl groups are optionally substituted with one to three groups selected from the group consisting of alkoxy, halogen, alkoxyalkyl, hydroxy, alkylthio, a 5- to 10-membered aromatic heterocyclic group containing one to three heteroatoms selected from a nitrogen atom, an oxygen atom, and a sulfur atom, a 5- to 7-membered saturated aliphatic heterocyclic group optionally substituted with acyl and contains one to three nitrogen atoms, and phenyl optionally substituted with halogen or alkoxy; R 3 and R 4 are the same or different and each represents hydrogen, alkyl, alkoxy, or halogen; and R 5 and R 6 represent any one of the following groups: (i) R 5 is combined with R 6 to represent alkylene, wherein the alkylene group is optionally substituted with hydroxy or oxo, and the alkylyene is optionally condensed with a benzene ring; (ii) R 5 is selected from the group consisting of hydrogen, hydroxy, alkyl, phenyl, an alkoxy, wherein the alkyl, phenyl and alkoxy is optionally substituted with one to three groups selected from the group consisting of alkoxy, alkylthio and halogen; and R 6 is selected from the group consisting of alkyl, cycloalkyl, phenyl, and a 5- to 10-membered aromatic heterocyclic group containing one to three heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom, wherein the alkyl, cycloalkyl, phenyl, and aromatic heterocyclic group is optionally substituted with one to three groups selected from the group consisting of alkoxy, hydroxy, phenyl, pyridyl, furyl, halogen, and N,N-dialkylamino.