METHOD OF PREPARING [5,6-DICARBOXY-3-PYRIDYL]AMMONIUM HALIDES AND METHOD OF PREPARING IMIDAZOLINONE COMPOUNDS Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: [(5,6-dicarboxy-3- pyridyl)methyl] ammonium halides of formula I: wherein R¹,R²,R³ are C_1-4 alkyl and, when taken together, R¹,R² form 5-or 6- membered ring optionally terminated by 0, S or NR³; R³ is C_1-4 alkyl; X is Cl, Br or J; Z is H or halogen; Z is H, halogen, cyano or nitro, are prepared by oxidation of compound of formula II: with hydrogen peroxide in the presence of aqueous base, compounds of formula I are useful as intermediate compounds for preparing herbicidal 5-(alkoxymethyl)-2- (2-imidazoline- 2-yl) nicotinic acids, esters and salts. EFFECT: improved properties of the title compounds. 11 cl, 8 ex