PROCESS FOR PREPARING PYRIDINE CARBOXYLIC DERIVATIVES

A method for preparing pyridine carboxylic acid esters by reacting N-hydroxyamino derivatives of the formula: wherein R5 and R6 are each independently H, COZ, or CN, provided that they are not both H; or R5 and R6 together are -CO-NR10-CO; Z is OR8 or NR8R9; R8 and R9are each independently H or alkyl or aryl; or R8 and R9 together with the nitrogen atom form an aliphatic or aromatic heterocyclic structures and R10 is hydrogen, alkyl, aryl, hydroxy or an alkoxy of 1-6 carbon atoms; with an alpha , beta -unsaturated aldehyde or ketone is disclosed. In an additional embodiment, an alkene of formula R5-CH=CH-R6, wherein R5 and R6 are defined as above, is reacted with hydroxylamine or a salt thereof to form N-hydroxylamino derivatives which are then treated as above.