反应详情

A mixture of 2-ethoxy-4-(diethylamino)benzaldehyde (7.87 g, 35.56 mmol), 1-cyclopentyl-3-ethyl-5-amino-1H-pyrazole-4-carboxamide (3.95 g, 17.78 mmol), p-toluenesulfonic acid monohydrate (0.05 g), 10% palladium on carbon (0.11 g) and benzene (150 ml) was refluxed overnight with the azeotropic removal of water. The catalyst was removed by filtration, and the filtrate was concentrated in vacuo. The residue was combined with that from a similar experimental run, and dissolved in CH2Cl2, and loaded onto a silica gel column. Elution of the column with ether/hexane (60/40) afforded a green foam which was titurated with refluxing hexane, and cooled and the product, as pale yellow needles, was collected by filtration to afford 1.19 g (8%) of 1-cyclopentyl-3-ethyl-6-[2-ethoxy-4-(diethylamino)phenyl]pyrazolo[3,4-d]pyrimidin-4-one, m.p. 138-139° C.

1. customThe catalyst was removed by filtration
2. concentrationthe filtrate was concentrated in vacuo
3. dissolutiondissolved in CH2Cl2
4. washElution of the column with ether/hexane (60/40)
5. customafforded a green foam which
6. temperaturecooled
7. filtrationthe product, as pale yellow needles, was collected by filtration