反应详情

To a suspension of 3.7 g (0.0172 mole) of 2-(1-hydroxyethyl)-6-methylpyrazolo[1,5-c]quinazolin-5(6H)-one in 30 ml of benzene there is added 2.6 g (0.036 mole) of solid, 90% sodium cyanate followed by the dropwise addition of 3.1 ml (0.041 mole) of trifluoroacetic acid. The reaction mixture is stirred on a magnetic stirrer at approximately 120 revolutions per minute for 2 hours at room temperature. By the end of this time a gum separates. The reaction mixture is subsequently treated with 15 ml of water with increased stirring speed after which a solid (insoluble in either phase) forms. This is filtered, washed with water and air dried to give 2.9 g (60% direct yield), m.p. 216°-221°. The solid is twice crystallized from chloroform-methanol (1:1) to give 2.0 g of analytically pure material, m.p. 250°-252°.

1. temperaturewith increased
2. stirringstirring speed after which a solid (insoluble in either phase) forms
3. filtrationThis is filtered
4. washwashed with water and air
5. customdried
6. customto give
7. custom2.9 g (60% direct yield), m.p. 216°-221°
8. customThe solid is twice crystallized from chloroform-methanol (1:1)
9. customto give 2.0 g of analytically pure material, m.p. 250°-252°