摘要 |
PROBLEM TO BE SOLVED: To obtain a new compound useful as an intermediate for agrochemicals and medicines. SOLUTION: This compound is represented by formula I (R is an alkyl having a 3-5C branched chain; X is a halogen), e.g. 2-tertiary butyl-4,5-dichloro-6-nitro-3(2 H)-pyridazinone. The compound of formula I is obtained by reacting a compound of formula II [e.g. 2-tertiary butyl-4,5-dichloro-3(2H)-pyridazinone] with a nitrogen oxide such as N2 O4 and oxygen and/or air containing ozone in the presence of a metal (preferably iron, etc.), and/or a metal compound (preferably a heteropolyacid, etc., comprising Mo, etc.), and an inorganic acid and an organic acid (preferably methanesulfonic acid, etc.), as catalysts, preferably at a temp. of -20 to 30 deg.C. It is preferable to use an organic solvent when the compound of the formula II is solid, and an aliphatic nitro compound such as nitromethane is preferable as the solvent. |