反应详情

The starting 2-chloro-3-(2'-amino-4'-chlorophenoxy)-pyridine of the formula (400) is prepared as follows: With stirring, a mixture of 25.9 g (0.2 mole) of 2-chloro-3-hydroxypyridine and 38.4 g (0.2 mole) of 2,5-dichloronitrobenzene is heated to 120°-125° C. and to this mixture is added a solution of 13.17 g of solid 85% potassium hydroxide in 10 ml of water in the course of 2 hours. The hot suspension is mixed in a mixer with 300 ml of water. The crystalline precipitate is collected by filtration and washed with 1000 ml of water. A solution of 14.25 g (0.05 mole) of the resultant 2-chloro-3-(2-nitro-4-chlorophenoxy)-pyridine in 75 ml of dioxane is then hydrogenated in the presence of 15 g of Raney nickel. The catalyst is then removed by filtration, the filtrate is distilled and the precipitated crystalline product is collected by filtration and dried, affording 8.3 g of 2-chloro-3-(2'-amino-4'-chlorophenoxy)-pyridine of the formula (400) with a boiling point of 163°-167° C./50.76 kPa.

1. temperatureis heated to 120°-125° C. and to this mixture
2. filtrationThe crystalline precipitate is collected by filtration
3. washwashed with 1000 ml of water
4. customThe catalyst is then removed by filtration
5. distillationthe filtrate is distilled
6. filtrationthe precipitated crystalline product is collected by filtration
7. customdried