反应详情

2.0 g (0.0093 mole) of 2-(hydroxymethyl)pyrazolo[1,5-c]-quinazolin-5(6H)-one prepared as described in Example 6B and 1.55 ml (≅ 1.7 g or 0.014 mole) of 98% phenylisocyanate are refluxed in 20 ml of dry pyridine under N2 for 1 hour. The crude product is poured onto 200 ml of ice-water layered with ethyl acetate (50 ml) and stirred for 30 minutes. The precipitates that form are filtered off, air-dried and taken up in dioxane (150 ml). The solution is filtered while hot and the clear filtrate concentrated down to a volume of 100 ml and cooled. The precipitates are filtered off and dried in vacuo at 85°. Yield 2.45 g, 78.8% crude yield.

1. customThe precipitates that form
2. filtrationare filtered off
3. customair-dried
4. filtrationThe solution is filtered while hot and the clear filtrate
5. concentrationconcentrated down to a volume of 100 ml
6. temperaturecooled
7. filtrationThe precipitates are filtered off
8. customdried in vacuo at 85°