2,5-Dichloronitrobenzene → 2-Chloro-3-(2'-amino-4'-chlorophenoxy)-pyridine

関与物質

反応手順

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.

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