Abstract
The synthesis of 3,4-dihydropyrimidin-2-(1H)-ones derivatives via a three-component Biginelli reaction using copper nitrate as a catalyst under solventless conditions is reported, providing a green, rapid, efficient, and convenient method for the preparation of Biginelli compounds in good yields.
ACKNOWLEDGMENT
We are grateful for financial support from the National Nature Science Foundation of China (Grants 20772024 and 20802016).
Notes
a Reaction conditions: benzaldehyde (3 mmol), ethyl acetoacetate (4.5 mmol), urea (6 mmol), and catalyst stirring in solvent (2 mL, entries 12–16) at 70 °C.
b Isolated yield.
c Room temperature.
a Reaction conditions: aldehyde (3 mmol), ethyl acetoacetate or acetylacetone (4.5 mmol), urea or thiourea (6 mmol), and Cu(NO3)2·3H2O (5 mol%) stirring without a solvent at 70 °C.
b Isolated yield.
c 90 °C.