| 摘要 |
NEW MATERIAL:A compound shown by formula I [R<1> is alkyl, lower alkenyl, cycloalkyl, (substituted)aryl, 5- or 6-heterocyclic group, etc.; R<2>-R<4> are H, halogen, cyano, nitro amino, lower alkyl, OH, etc.; R<5> and R<6> are lower alkyl, halogenated lower alkyl, cycloalkyl, (substituted)aryl, etc.; group shown by formula II is carboxy group or esterified carboxyl group] or an l-oxide or a salt thereof. EXAMPLE:4-Butyl-5-( 2,6-diethylphenylcarbamoyl )-2,6-dimethyl-3-pyridinecarboxy lic acid methyl ester. USE:A plant growth regulator. PREPARATION:A 1,4-dihydropyridine derivative shown by formula III (group shown by formula IV is esterified carboxyl group) is oxidized with an oxidizing agent such as nitrous acid, sulful, etc., to give a compound shown by formula I when a group shown by formula II is group shown by formula IV. |
