反应详情

A mixture of 20 parts of 2-amino-3,5-dichloropyridine, 160 parts of glycol, 80 parts of potassium hydroxide, 1 part of copper powder and 3 parts of diethylene glycol dimethyl ether is stirred under nitrogen for 5 hours at 150°-160° C. The cooled solution is neutralised with conc. hydrochloric acid, saturated with sodium chloride and extracted twice in the warm state with ethyl acetate. The combined extracts are filtered through Hyflo, dried over magnesium sulphate and purified with active charcoal. The solvent is evaporated off to leave 12.3 parts (70% of theory) of 2-amino-3-hydroxy-5-chloropyridine, m.p. 198°-201° C.

1. extractionextracted twice in the warm state with ethyl acetate
2. filtrationThe combined extracts are filtered through Hyflo
3. dry with materialdried over magnesium sulphate
4. custompurified with active charcoal
5. customThe solvent is evaporated off