Process for preparing pyridine-2,3-dicarboxylic acid compounds
AssigneeSugai Chemical Ind. Co., Ltd.
InventorsTakaharu Yamashita, Mitsuhiro Kodama, Shouzo Shimada
Life of this patent
Estimating the term…
Abstract
A process for preparing pyridine-2,3-dicarboxylic acid compounds of the following formula: ##STR1## wherein R.sup.1 and R.sup.3 are, identical or different, each a hydrogen atom or a lower alkyl group, R.sup.2 is a hydrogen atom, a lower alkyl group, or a phenyl-(lower)alkyl group which may have halogen atom or lower alkyl group on its phenyl ring, and R.sup.4 and R.sup.5 are, identical or different, each a lower alkoxy group. The compounds are useful as an intermediate for preparing agricultural chemicals and pharmaceuticals.
Claims9
A process for preparing pyridine-2,3-dicarboxylic acid compounds of the formula (1). ##STR12## wherein R.sup.1 and R.sup.3 are, identical or different, each a hydrogen atom or a lower alkyl group, R.sup.2 is a hydrogen atom, a lower alkyl group, or a phenyl-(lower)alkyl group which may have a halogen atom or a lower alkyl group on its phenyl ring, and R.sup.4 and R.sup.5 are, identical or different, each a lower alkoxy group;
- comprising reacting a compound of the formula (2):
- ##STR13## wherein R.sup.1, R.sup.2, and R.sup.3 are same as defined above, with a compound of the formula (3):
- ##STR14## wherein R.sup.4 and R.sup.5 are same as defined above, and X is a halogen atom in the presence of a sufficient amount of ammonia in an aprotic organic solvent under a reaction temperature of from about 20.degree. C. to about 200.degree. C. until the reaction is essentially complete.
Dependencies are inferred from the claim text.