反应详情

温度

-20 °C

Anhydrous cyanamide (32 g, 0.76 mol) was dissolved in acetonitrile (600 ml) in a 2 l, 3-necked flask equipped with a mechanical stirrer, drying tube, and two dropping funnels. The solution was cooled in a 1:1 ethanol-water bath that was maintained at -20° C. by the addition of dry ice. Solutions of pyridine (57 g, 0.72 mol) in acetonitrile (70 ml) and of 4-pyridylmethanesulfonyl chloride triflate (130 g, 0.38 mol) in acetonitrile (200 ml) were added simultaneously at such a rate that the additions of both solutions were completed in 3 hrs. The resulting suspension was stirred at -10° C. for 1 hr and then filtered and the solids washed with cold acetonitrile (50 ml). The solid portion was recrystallized by adding it to ice-cold water (100 ml). The product was filtered off and washed with ice-water (100 ml) to give a light yellow solid (49.5 g). The mother liquors were refrigerated overnight to give additional product (5 g, 73% total yield).

1. customequipped with a mechanical stirrer
2. customdrying tube
3. temperatureThe solution was cooled in a 1:1 ethanol-water bath that
4. filtrationfiltered
5. washthe solids washed with cold acetonitrile (50 ml)
6. customThe solid portion was recrystallized
7. additionby adding it to ice-cold water (100 ml)
8. filtrationThe product was filtered off
9. washwashed with ice-water (100 ml)