反应详情

温度

90 °C

Following the method of Sansebastiano et al. (Il Farmaco 1993, 48, 335), to a stirred solution of 2.44 g (10.3 mmol) 3-dimethylamino-2-(furan-2-carbonyl)-acrylic acid ethyl ester and 2.26 g (18.5 mmol) guanidine nitrate in 20 ml DMF was added 1.51 g (18.5 mmol) sodium acetate and the mixture heated at 90° C. for 36 h. The reaction mixture was then partitioned between ether and water. The phases were separated and the aqueous phase extracted twice more with ethyl acetate. The combined organic phases were dried over sodium sulfate and concentrated in vacuo. The residue was recrystallised from ether/ethyl acetate/hexane to afford 669 mg (28%) 2-amino-4-furan-2-yl-pyrimidine-5-carboxylic acid ethyl ester as a white crystalline solid. Chromatography (ethyl acetate/hexane 2/1) of the mother liquor afforded a further 150 mg (6%) product. ES-MS m/e (%): 234 (M+H+, 100), 206 ([M—C2H4]+, 35), 188 ([M+H-EtOH]+, 42).

1. customThe reaction mixture was then partitioned between ether and water
2. customThe phases were separated
3. extractionthe aqueous phase extracted twice more with ethyl acetate
4. dry with materialThe combined organic phases were dried over sodium sulfate
5. concentrationconcentrated in vacuo
6. customThe residue was recrystallised from ether/ethyl acetate/hexane