| 摘要 |
1375157 Amino benzimidazoles and imidazo- (4,5-b)pyridines ELI LILLY & CO 23 Dec 1971 [28 Dec 1970] 38094/73 Divided out of 1374800 Heading C2C A process for preparing benzimidazole and imidazo-(4,5-b)pyridines of the general formulµ involves treating an ether of general formula with ammonia, a primary or secondary amine, wherein R<SP>1</SP> is H, Cl, F, C 1-6 perfluoroalkyl or a radical -(CHZ) n CH 2 Z in which Z is H or halogen and n is 0 or 1; each R<SP>3</SP> is halogen; each R<SP>4</SP> is nitro, CF 3 , CF 2 Cl or CF 2 H; R<SP>5</SP> is cyano or C 1-4 alkylsulphonyl; m = 0 or an integer 1-3, n= 0, 1 or 2 and r=0 0 or 1, the sum of m, n and r being 0 to 3; R<SP>6</SP> is halogen, nitro, CF 3 , CF 2 , Cl, CF 2 H or C 1-4 alkylsulphonyl, providing not more than one R<SP>6</SP> is nitro, CF 3 , CF 2 Cl, CF 2 H or alkylsulphonyl and R<SP>2</SP> is C 1-8 alkyl, C 2-8 alkenyl, C 5-6 cycloalkyl, benzyl, phenethyl or tetrahydro- 2-pyranyl and Y is the residue of ammonia, a primary or secondary amine. In the examples 1 - methoxy - 6 - chloro - 2(trifluoromethyl) - 1H- imidazo-(4,5-b)pyridine is treated with ammonium hydroxide to give 5-amino-6-chloro-2- (trifluoromethyl)-1H-imidazo-(4,5-b)pyridine. 1 - Hydrozy - 6 - chloro - 2 - (trifluoromethyl)- 1H-imidazo-(4,5-b)pyridine is prepared by reductive cyclization of 5-chloro-3-nitro-2-(trifluoroacetamido)pyridine. Reference has been directed by the Comptroller to Specification 1,307,489. |
