反应详情

To a mixture of 12.8 g (86.4 mmol) of 2-cyclopropyl-6-methylphenol and 1,2-dichlorobenzene (78.3 mL) was added 15.3 g (86.4 mmol) of 95% cesium hydroxide at room temperature. The resultant mixture was heated to 180° C. and subjected to azeotropic dehydration under reflux while stirring for 30 minutes. To the resultant solution was added dropwise the preliminarily prepared solution of 5.00 g (purity: 95.0%; 28.8 mmol) of 4-hydroxy-3,6-dichloropyridazine in t-butanol (95.0 g) at 180° C. over 2 hours. (The t-butanol was distilled off simultaneously with the dropwise addition of the solution.) After stirring at 180° C. for another 2 hours, the reaction mixture was cooled to room temperature, and 100 g of pure water was added to the cooled mixture and stirred for 30 minutes, and an organic phase containing 2-cyclopropyl-6-methylphenol added in an excess amount was separated. 50.0 g of toluene was added to the resultant aqueous phase and stirred at room temperature for 30 minutes, and an organic phase containing 2-cyclopropyl-6-methylphenol was separated. This operation was repeated twice. Then, the resultant aqueous phase containing a cesium salt of 6-chloro-3-(2-cyclopropyl-6-methylphenoxy)-4-pyridazinol was added dropwise to a 4% aqueous hydrochloric acid solution at 0° C. to deposit solids, followed by filtration. The resultant solids were washed with pure water and dried under a reduced pressure, and dissolved in an organic solvent and quantitatively determined by an HPLC internal standard analysis method, which showed that 7.92 g of 6-chloro-3-(2-cyclopropyl-6-methylphenoxy)-4-pyridazinol (purity: 76.1%; yield: 76%) and 166 mg of 3-chloro-6-(2-cyclopropyl-6-methylphenoxy)-4-pyridazinol (yield: 2.1%) were obtained.

1. temperatureunder reflux
2. distillation(The t-butanol was distilled off simultaneously with the dropwise addition of the solution
3. stirring) After stirring at 180° C. for another 2 hours
4. addition100 g of pure water was added to the cooled mixture
5. stirringstirred for 30 minutes
6. additionan organic phase containing 2-cyclopropyl-6-methylphenol
7. additionadded in an excess amount
8. customwas separated
9. addition50.0 g of toluene was added to the resultant aqueous phase
10. stirringstirred at room temperature for 30 minutes
11. additionan organic phase containing 2-cyclopropyl-6-methylphenol
12. customwas separated
13. additionThen, the resultant aqueous phase containing a cesium salt of 6-chloro-3-(2-cyclopropyl-6-methylphenoxy)-4-pyridazinol
14. additionwas added dropwise to a 4% aqueous hydrochloric acid solution at 0° C.
15. filtrationfollowed by filtration
16. washThe resultant solids were washed with pure water
17. customdried under a reduced pressure
18. dissolutiondissolved in an organic solvent