反应详情

Compound III is synthesized according to the procedure of Pfeiderer (Pfeilderer, W. (1957) Chem. Ber., 90:2272-2276) as follows. 12.2 g of o-methylisourea hydrochloride (110.6 mmol), 11.81 mL methylcyanoacetate (134 mmol), 12.45 g of sodium methoxide (230.5 mmol) and 80 mL of methanol are placed in a 250 mL round bottom flask. The suspension is stirred and refluxed for 5 hours at 68°-70° C. After cooling at room temperatute, the suspension is filtered through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL), and the NaCl on the filter is washed with methanol. The filtrate is filtered by gravity through a Whatman™ no. 1 paper in a 500 mL round bottom flask, and the solvent is evaporated under reduced pressure with a rotary evaporator at 50° C. The residue is solubilized with warm distilled water, and the product is precipitatedd by acidification to pH 3-4 with glacial acetic acid. After 2 hours (or overnight) at room temperature, the suspension is filtered under vacuum through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL). The product is washed with water, acetone, and dried. The product is recrystallized with water as the solvent and using charcoal for decolorizing (activated carbon, NoritrA<100 mesh, decolorizing). The yield is 76%.

1. temperaturerefluxed for 5 hours at 68°-70° C
2. temperatureAfter cooling at room temperatute
3. filtrationthe suspension is filtered through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL)
4. washthe NaCl on the filter is washed with methanol
5. filtrationThe filtrate is filtered by gravity through a Whatman™ no
6. custom1 paper in a 500 mL round bottom flask, and the solvent is evaporated under reduced pressure with a rotary evaporator at 50° C
7. temperaturewith warm
8. distillationdistilled water
9. filtrationthe suspension is filtered under vacuum through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL)
10. washThe product is washed with water, acetone
11. customdried
12. customThe product is recrystallized with water as the solvent