反应详情

6,6'-Dimethyl-4-ethoxy-2,2'-bipyridine-N-oxide (21) (0.96 g, 3.93 mmoles) was dissolved in chloroform (34 ml). After addition of phosphorus tribromide (3.0 ml) the mixture was refluxed for 1.5 hours. The solution was poured on ice, some chloroform was added and the phases were separated. The chloroform phase was extracted with water. The aqueous phases were combined, made alkaline with sodium hydroxide solution, and extracted with chloroform. Evaporation of the organic phase followed by silica gel chromatography yielded pure title product. Yield: 69%

1. temperaturewas refluxed for 1.5 hours
2. additionThe solution was poured on ice
3. customthe phases were separated
4. extractionThe chloroform phase was extracted with water
5. extractionextracted with chloroform
6. customEvaporation of the organic phase