| 摘要 |
PURPOSE:To obtain the titled compound including novel substance, in high yield, by diazotizing 1-(2-fluoro-5-aminophenyl)-3-methyl- <2>-1,2,4-triazolin-5-one derivative and thermally decomposing the product in the presence of copper sulfate. CONSTITUTION:A 1-(2-fluoro-5-aminophenyl)-3-methyl- <2>-1,2,4-triazolin-5-one derivative of formula II (R is 1-5C haloalkyl) is diazotized e.g. by reacting 1mol of the compound of formula II with 1.0-2.0mol of NaNO2 in an aqueous solution of 1.5-15mol of sulfuric acid preferably under cooling. The obtained diazonium salt of formula III is optionally separated from the reaction mixture and is thermally decomposed in the presence of 0.1-6mol of copper sulfate (based on 1mol of the compound of formula II) at room temperature -200 deg.C for 0.5-6hr. After the completion of the reaction, the reaction mixture is extracted with a solvent such as ethyl acetate, dried, and the extraction solvent. is distilled off to obtain the objective compound of formula I including novel compound and useful as an intermediate for herbicide. |
