Patent ID: 6392050
Filing Date: 2002-05-21
Classification: C07D

Abstract:
A process for preparing a substituted pyridine of formula (I) whereinR1 and R5 are identical or different and each represents C1-C10-alkyl or C6-C10-aryl, R2 and R4 are identical or different and each represents hydrogen, C1-C10-alkyl, CN, or COOR6 wherein R6 is C1-C1-alkyl, and R3 represents hydrogen, C1-C10-alkyl or represents C6-C10-aryl that is optionally substituted by halogen, nitro, COOR6 (wherein R6 is C1-C10-alkyl), CN, or C1-C10-alkyl, comprising reacting a substituted 1,4-dihydropyridine of formula (II) wherein R1 to R5 are as defined for formula (I), with methyl nitrite in the presence of an acid containing less than 20% by weight of oxidizing components.