Patent ID: 8431586

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 represents any one of the following groups: (i) R 5 is selected from the group consisting of hydrogen, alkyl, and phenyl, wherein the alkyl and phenyl is optionally substituted with one to three groups selected from the group consisting of alkoxy, alkylthio and halogen; and R 6 is —N(R 6-1 )(R 6-2 ), wherein R 6-1 is hydrogen or alkyl and R 6-2 is an alkoxy optionally substituted with one to three groups selected from the group consisting of alkoxy, alkylthio and halogen; or R 6-1 is combined with R 6-2 to represent —O—(CH 2 ) n —, wherein n is 3 to 5; or (ii) R 5 is selected from the group consisting of hydroxy and alkoxy, wherein the alkoxy is optionally substituted with one to three groups selected from the group consisting of alkoxy, alkylthio and halogen; and R 6 is —N(R 6-1 )(R 6-2 ), wherein R 6-1 is hydrogen or alkyl and R 6-2 is hydrogen or alkoxy optionally substituted with one to three groups selected from the group consisting of alkoxy, alkylthio and halogen.