Patent ID: 8058432
Filing Date: 2011-11-15
Classification: A61P,C07C,C07D,Y02P

Abstract:
1. A method for preparing a compound represented by the following formula (1) or a pharmaceutically acceptable salt thereof, comprising: wherein R1 represents either a phenyl group which may have a substituent or a pyridyl group which may have a substituent; R2 represents an alkyl group which may have a substituent; R3 represents an alkyl group substituted with a di-alkylamino group, an alkyl group substituted with a mono-alkylamino group or an alkyl group substituted with an amino group; and R4 represents a hydrogen atom, an alkyl group or a benzyl group which may have a substituent; (a) reacting a compound represented by the following formula (2) or a chemically acceptable salt thereof: wherein R1 and R2 are the same as those defined above, with a carbonyl group-introducing reagent and a compound represented by the following formula (3) or a chemically acceptable salt thereof: wherein R3′ represents an alkyl group substituted with a dialkylamino group, an alkyl group substituted with a mono-alkylamino group which may have a protective group or an alkyl group substituted with an amino group which may have a protective group, to thus form a compound represented by the following formula (4) or a chemically acceptable salt thereof: wherein R1, R2 and R3′ are the same as those defined above; (b) converting the compound of Formula (4) into a quinazoline-dione compound represented by the following formula (5) or a pharmaceutically acceptable salt thereof, in the presence of a carboxyl group-activating agent: wherein R1 to R3′ are the same as those defined above; and (c) if desired, substituting an N-alkyl group for the hydrogen atom bonded to the nitrogen atom present in the quinazoline-dione ring of the compound of Formula (5) using an N-alkylation agent and then deprotecting the resulting product, when the substituent R3′ is protected.