反应详情

A suspension of 2,6-Dinitro-4-pyridin-3-yl-aniline (1.24 g, 4.76 mmol) in aqueous sulfuric acid (50% v/v, 12 ml) was stirred at ambient temperature for 1 h before being cooled in an ice bath and treated over 5 min with an aqueous sodium nitrite solution (20% w/v, 2.0 ml). The mixture was stirred in the cold for 1.5 h before being treated with a solution of potassium thiocyanate (0.6 g) in water (1.4 ml) in one portion. The resultant mixture was stirred in the cold for 15 min and then added to a suspension of copper (I) thiocyanate (1.0 g) in water (4 ml) whilst cooling in an ice-bath. The mixture was stirred in the cold for 2 h and then heated to 70° C. for 20 min. After cooling to ambient temperature, the mixture was poured into a saturated aqueous solution of sodium hydrogen carbonate (200 ml) and extracted with ethyl acetate (3×100 ml) which was washed with brine (200 ml) and dried (MgSO4). The solvent was removed in vacuo to give a residue which was purified by flash chromatography (silica) eluting with 80% to 100% ethyl acetate in 40-60 petroleum ether. The 3-(3,5-Dinitro-4-thiocyanato-phenyl)-pyridine was obtained as a yellow solid (1.07 g, 74%).

1. temperaturebefore being cooled in an ice bath
2. stirringThe mixture was stirred in the cold for 1.5 h
3. temperaturewhilst cooling in an ice-bath
4. stirringThe mixture was stirred in the cold for 2 h
5. temperatureheated to 70° C. for 20 min
6. temperatureAfter cooling to ambient temperature
7. extractionextracted with ethyl acetate (3×100 ml) which
8. washwas washed with brine (200 ml)
9. dry with materialdried (MgSO4)
10. customThe solvent was removed in vacuo
11. customto give a residue which
12. customwas purified by flash chromatography (silica)
13. washeluting with 80% to 100% ethyl acetate in 40-60 petroleum ether