反应详情

温度

42 °C

Anhydrous sodium carbonate (5.83 g, 0.055 mole), methanol (60 mL), and 35% aqueous hydrazine (11.0 g, 0.120 mole) were loaded into a 500 mL three necked flask equipped with a thermometer, magnetic stirrer, condenser, and addition funnel. A solution/partial slurry of 2,4-dichloro-5-methoxy-pyrimidine (17.91 g, 0.100 mole) in toluene (30 mL) was added dropwise over 39 min. During the addition, the reaction temperature rose from 15° C. to 39° C. and the solids dissolved to form a clear, pale yellow solution. The reaction mixture was heated to 42° C. for 4.1 h, after which the heat source was removed. Slow, dropwise addition of water (180 mL), caused the product to crystallize out of solution. The resulting slurry was stirred for 2 h at room temperature, then the product was recovered by filtration through Whatman #1 filter paper using a Buchner funnel and aspirator vacuum. After washing the filter cake with water, the product was dried overnight in vacuo at 40° C., to give 15.02 g of white 2-chloro-4-hydrazino-5-methoxypyrimidine (purity 96.2%, yield=82.8%): 1H NMR (300 MHz, DMSO-d6) 3.33 (s, 3H), 3.78 (s, 3H), 4.39 (br s, 2H), 7.59 (s, 1H), 8.73 (br s, 1H).

1. customequipped with a thermometer, magnetic stirrer, condenser, and addition funnel
2. additionDuring the addition
3. customrose from 15° C. to 39° C.
4. dissolutionthe solids dissolved
5. customto form a clear, pale yellow solution
6. customafter which the heat source was removed
7. additionSlow, dropwise addition of water (180 mL)
8. customto crystallize out of solution
9. filtrationthe product was recovered by filtration through Whatman #1
10. filtrationfilter paper
11. washAfter washing the filter cake with water
12. customthe product was dried overnight in vacuo at 40° C.