Patent ID: 7309788

Claim:
A process for preparing pyrimidinone compound of Formula 1 and pharmaceutically acceptable salts and hydrates thereof, comprising the steps of thioamidating a compound of Formula 7 by using Lawessons's reagent and then treating the product with alcoholic reagent, as illustrated in the following Reaction Scheme 2: wherein, R 1 is C 1 -C 4 straight or side chain alkyl,cycloalkyl, C 1 -C 4 alkylalkoxy or C 1 -C 4 alkylmercapto; R 2 is H, halogen, C 1 -C 4 straight or side chain alkyl or arylalkyl; R 3 and R 4 which are the same or different from each other, represent H, C 1 -C 4 straight or side chain alkyl, cycloalkyl, arylalkyl, or C 1 -C 4 alkoxycarbonyl, being optionally substituted by H, halogen, hydroxy, C 1 -C 4 alkoxy, amino, alkylamino or dialkylamino (each alkyl group having C 1 -C 5 ), or R 3 and R 4 together with the nitrogen to which they are attached form a 4 to 8 membered heterocyclic ring which can be further substituted with one or two substituents selected from the group consisting of cycloalkyl, arylalkyl, halogen, hydroxy, C 1 -C 4 alkoxy, amino, alkylamino dialkylamino (each alkyl group having C 1 -C 5 ), and C 1 -C 4 straight or side chain alkyl, wherein said heterocyclic ring can further include—O—,—S—,—SO—,—SO 2 — or —N(R 5 )—; R 5 is H, C 1 -C 4 alkyl, carbocyclic aryl, arylalkyl, substituted alkenyl, pyridyl, pyrimidyl, or C 1 -C 4 alkyl; and n is an integer selected from 1, 2, 3, 4, 5 and 6.