2 6-DICHLORO-4-NITROPYRIDINE 97

2587-00-0

25194-01-8

The general procedure for the synthesis of 2,6-dichloro-4-nitropyridine from 2,6-dichloropyridine-N-oxide was as follows: 2,6-dichloropyridine-N-oxide (12.8 g, 78 mmol) was added to a mixed solution consisting of 95% concentrated nitric acid (21 mL) and 98% concentrated sulfuric acid (50 mL). The reaction was stirred at 148 °C for 1 h. The temperature was subsequently raised to 156 °C until no more nitrogen dioxide gas was released. After completion of the reaction, the reaction solution was cooled to room temperature and slowly poured into 150 g of ice water. The pH of the mixture was adjusted to 6 with ammonia, at which point a solid product precipitated. The solid was collected by filtration and the resulting crude product was recrystallized with petroleum ether to give 10 g of yellow solid product in 66.4% yield.