The Biginelli reaction is a one-pot (three-component) procedure that in the presence of an acid catalyst, converts a β-keto ester, an aryl aldehyde, and urea to a hexahydropyrimidine derivative. First, urea reacts with the aldehyde affording an aminal, which dehydrates to an N-acyliminium ion. The enol form of the β-keto ester then attacks the N-acyliminium intermediate, making an open chain ureide, which cyclizes to a hexahydropyrimidine derivative.
- Reagents: Catalytic Acid (HCl, H2SO4, TsOH, LiBr, etc.), Alcohol Solvent (e.g. Ethanol)
- Reactant: β-Keto Ester, Aryl/Heteroaromatic/Aliphatic Aldehyde, Urea (Monosubstituted, Thiourea)
- Product: Hexahydropyrimidine Derivative
- Type of Reaction: Condensation
Mechanism
Top Citations
Original Paper
Related Reactions
- Biginelli Pyrimidone synthesis
- Passerini Reaction
- Ugi Reaction
- Multicomponent Reactions
Related Compounds
- Oximes
