PRODUCTION OF PYRIDINE-2,3-DICARBOXYLIC ESTER

• Main Authors: RODUIT JEAN-PAUL DR, BESSARD IVES DR, STUCKY GERHARD DR
• Format: Patent
• Language: English
• Published: 17.03.1998
• Edition: 6
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR RELEVANT APPARATUS; TRANSPORTING

PROBLEM TO BE SOLVED: To obtain the subject new compound useful as e.g. a herbicide by reaction between 2,3-dichloropyridine as a readily available starting material, carbon monoxide and an alcohol in the presence of a catalyst and a base. SOLUTION: This new compound is a pyridine-2,3-dicarboxylic ester of formula I (R is a 1-6C alkyl, a 3-6C cycloalkyl, etc.; R to R are each H, a 1-6C alkyl, etc.), e.g. 2,3-dichloro-5 (methoxymethyl)pyridine. The compound of formula I is obtained by reaction between a 2-halopyridine of formula II, CO and an alcohol of the formula ROH by the use of a catalyst, a catalytically active complex of Pd and a diphosphine of the formula R R P-Q-PR R [R to R are each phenyl, a 1-6C alkyl, etc.; Q is 1,1'-ferrocenediyl or [CH2 ]n ((n) is 3 or 4)], in the presence of a base (an alkali metal acetate) in an alcohol as solvent at 80-250 deg.C under a pressure of 1-50atm for several hours. In this case, the proportion of the Pd to be used to the halogen compound of formula II is 0.2-10mol%.