Patent ID: 6743920
Filing Date: 2004-06-01
Classification: C07D

Abstract:
A process for preparing a 1H-imidazo[4,5-c]pyridin4-amine compound of Formula I or a pharmaceutically acceptable salt thereof whereinR1 is selected from hydrogen; CHRxRy wherein Rx is hydrogen and Ry is selected from alkyl or cyclic alkyl containing one to ten carbon atoms, straight chain or branched chain alkenyl containing two to ten carbon atoms, hydroxyalkyl containing one to six carbon atoms, alkoxyalkyl wherein the alkoxy moiety contains one to four carbon atoms and the alkyl moiety contains one to six carbon atoms, benzyl, and phenylethyl; and â€”C&boxH;CRzRz wherein each Rz is independently alkyl or cyclic alkyl of one to six carbon atoms; R2 is selected from hydrogen; alkyl containing one to eight carbon atoms; hydroxyalkyl containing one to six carbon atoms; alkoxyalkyl wherein the alkoxy moiety contains one to four carbon atoms and the alkyl moiety contains one to six carbon atoms; benzyl, phenylethyl; and phenyl; the benzyl, phenylethyl, or phenyl substituent being optionally substituted on the benzene ring by a moiety selected from methyl, methoxy, and halogen; and morpholinoalkyl wherein the alkyl moiety contains one to four carbon atoms; R3 and R4 are independently selected from hydrogen and alkyl of one to five carbon atoms; which process comprises the steps of: (1) providing a compound of Formula II wherein R3 and R4 are as described above; (2) reacting the compound of the Formula II with a chlorinating agent to provide a compound of Formula III (3) reacting the compound of the Formula III with a compound of formula R1NH2, wherein R1 is as defined above, to provide a compound of Formula IV (4) reacting the compound of the Formula IV with an alkali metal phenoxide to provide a compound of Formula V (5) reducing the compound of the Formula V to provide a compound of Formula VI (6) reacting the compound of the Formula VI with a carboxylic acid of the formula R2CO2H; an equivalent thereof selected from the corresponding acyl halide, R2C(O-alkyl)3, and R2C(O-alkyl)2(O(O&boxH;)C-alkyl); or a mixture thereof, wherein R2 is as defined above and each alkyl contains 1 to 8 carbon atoms, to provide a compound of Formula VIII (7) reacting the compound of the Formula VIII with an aminating agent to provide a compound of the Formula I.