反应详情

温度

180 °C

A mixture consisting of 42.4 gm (0.2 mol) of 2,6-dihydroxy-4-phenyl-3-cyano-pyridine and 300 ml of phosphorus oxychloride was heated for 6 hours at about 180° C. in a pressure vessel made of glass, while shaking the vessel. Thereafter, the reaction mixture was allowed to cool and was then added in small portions to a mixture of ice and water (about 3 liters), while stirring. The precipitate formed thereby was collected by suction filtration, washed with water and dried, yielding 47.4 gm (95% of theory) of the raw reaction product. The raw product was dissolved in chloroform (the small amount of insoluble matter was filtered off) and purified by passing the solution through a short silicagel column with chloroform as the flow agent. The combined chloroform fractions were evaporated, leaving as a residue 37.5 gm (75% of theory) of virtually colorless crystalline 2,6-dichloro-4-phenyl-3-cyano-pyridine of the formula ##STR5## which had a melting point of 167°-169° C.

1. temperatureto cool
2. stirringwhile stirring
3. customThe precipitate formed
4. filtrationthereby was collected by suction filtration
5. washwashed with water
6. customdried
7. customyielding 47.4 gm (95% of theory) of the raw
8. customreaction product
9. filtrationwas filtered off) and
10. custompurified
11. customThe combined chloroform fractions were evaporated