反应详情

3-chloro-4-cyanopyridine is converted to N-oxide by means of an oxidizing agent such as hydrogen peroxide or m-chloroperbenzoate, and phosphorus oxychloride is reacted thereto to obtain 4-cyano-2,3-dichloropyridine and 4-cyano-2,5-dichloropyridine. These compounds can be separated by column chromatography. The separated compounds are respectively hydrolyzed under an alkaline condition or an acidic condition to obtain the respective carboxylic acids, which are then subjected to Curtius rearrangement and then treated with trifluoroacetic acid to obtain 4-amino-2,3-dichloro-pyridine and 4-amino-2,5-dichloropyridine,

1. customis reacted