Organocatalytic Application of Ionic Liquids: [bmim][MeSO4] as a Recyclable Organocatalyst in the Multicomponent Reaction for the Preparation of Dihydropyrimidinones and -thiones
Sudipta Raha Roy, Pradeep S. Jadhavar, Kapileswar Seth, Kulin K. Sharma, Asit K. Chakraborti*
*Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar 160 062, Punjab, India, Email: akchakrabortiniper.ac.in
S. R. Roy, P. S. Jadhavar, K. Seth, K. K. Sharma, A. K. Chakraborti, Synthesis, 2011, 2261-2267.
1-butyl-3-methylimidazolium-based room-temperature ionic liquids as organocatalysts enable the synthesis of dihydropyrimidinones and -thiones by Biginelli multicomponent reactions involving an aldehyde, a β-keto ester or β-diketone, and urea or thiourea in excellent yields in short time. The ionic liquid can be recovered and reused for five consecutive reactions without significant loss of catalytic efficiency.
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