PURPOSE: To obtain the subject compound having an improved selectivity and weedkilling effect through reacting a specific pyridinedicarboxylic acid anhydride with amine in an inert organic solvent.
CONSTITUTION: This compound of formula I [R1 is H, an 1-4C alkoxy, (substituted) 1-6C alkyl, (substituted)3-8C cycloalkyl, (substituted)3-6C alkenyl or (substituted)alkynyl; and R2 to R4 are each H, a halogen, cyano, (substituted) 1-6C alkyl, (substituted)benzyl, (substituted)3-8C cycloalkyl or the like] is obtained by reacting (A) a pyridinedicarboxylic acid anhydride with (B) a primary amine of R2N-R1 e.g. at -20 to 120°C in an inert organic solvent (e.g. tetrachloroethane) and then subjecting the obtained pyridinedicarboxylic acid half amide of formula III to cyclization by a hydrolyzing agent (e.g. acetanhydride). It is pref. conducted in the component ratio A/B of (0.9 to 1) to (3 to 1) in a molar ratio of the material to the solvent of (0.2 to 2) to 1.
EEBAAHARUTO FUKUSU
MATEIASU GERUBAA
HERUMUUTO BUARUTAA
KAARUUOTSUTOO BUESUTOFUAREN
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