反应详情

温度

0 °C

2-Amino-5-(4-pyridyl)-1,3,4-thiadiazole (2.0 g, 11.2 mmol) was suspended in 48% aqueous hydrobromic acid (5.6 mL) and stirred at 0° C. Bromine (5.06 mL, 98.8 mmol) was added dropwise into the mixture at 0° C. Water (15 mL) was added slowly followed by a solution of sodium nitrite (1.97 g, 28.6 mmol) in water (2.8 mL). Stirring at 0° C. was continued for another 30 minutes. Sodium hydroxide (10.0 g) in water (10 mL) was added slowly into the reaction mixture while the temperature was maintained below 20° C. The reaction mixture was then extracted with chloroform then the chloroform solution was washed with water, dried (magnesium sulfate), filtered, and the solvent was evaporated. The residue was purified by flash chromatography using a gradient of ethyl acetate in hexane to give the title compound as a brown solid (1.28 g), m/z 242, 244 (MH+).

1. stirringStirring at 0° C.
2. temperaturewas maintained below 20° C
3. extractionThe reaction mixture was then extracted with chloroform
4. washthe chloroform solution was washed with water
5. dry with materialdried (magnesium sulfate)
6. filtrationfiltered
7. customthe solvent was evaporated
8. customThe residue was purified by flash chromatography