反应详情

400 g (2.6 mols) of 2,4-dichloro-thiazole are introduced in portions, in the course of one hour at between 15° and 20° C., into 2 liters of 98% strength nitric acid (density=1.51; about 47 mols), while stirring and cooling. Thereafter, the mixture is discharged in portions onto about 20 kg of ice/water, while stirring thoroughly and the precipitate formed is filtered off under suction while still cold, washed neutral with water and dried between clay plates. 494 g (95.5% of theory) of 2,4-dichloro-5-nitro-thiazole are obtained in this manner. Melting point of a sample recrystallized from low-boiling petroleum ether: 38°-39° C.

1. temperaturecooling
2. stirringwhile stirring thoroughly
3. customthe precipitate formed
4. filtrationis filtered off under suction while still cold,
5. washwashed neutral with water
6. customdried between clay plates