反应详情

温度

0 °C

A suspension of 1.5 g of the product from Example 9 in 33 mL of 1,2-dichloroethane was cooled to 0° C. under a nitrogen atmosphere and treated with 3.6 mL of trimethylaluminum (2M solution in toluene). The mixture was warmed briefly to 50°-60° C., recooled to room temperature, and treated with 1.4 g of 4-methoxy-6-methylpyrimidin-2-yl-carbamic acid, methyl ester. This reaction mixture was heated at reflux temperature for approximately 48 hours and was then cooled to 0° C. and acidified by the addition of 5% aqueous hydrochloric acid. The resulting precipitate was separated by filtration and washed with water and 1-chlorobutane. The filtrate was dried over magnesium sulfate, treated with carbon, and concentrated in vacuo to give a yellow gum. Crystallization from hot acetonitrile afforded 0.45 g of the title compound as an off-white solid, m.p. 178°-180° C.; NMR (CDCl3): δ 2.5 (3H, s), 2.8 (3 H, s), 3.9 (3H, s), 6.3 (1H, s), 7.5-7.8 (1H, br s), 7.6 (1H, t), 8.2 (2H, br d); IR(KBr): 1710 (carbonyl stretch) cm-1.

1. temperatureThe mixture was warmed briefly to 50°-60° C.
2. customrecooled to room temperature
3. temperatureThis reaction mixture was heated
4. temperatureat reflux temperature for approximately 48 hours
5. temperaturewas then cooled to 0° C.
6. customThe resulting precipitate was separated by filtration
7. washwashed with water and 1-chlorobutane
8. dry with materialThe filtrate was dried over magnesium sulfate
9. additiontreated with carbon
10. concentrationconcentrated in vacuo
11. customto give a yellow gum
12. customCrystallization from hot acetonitrile