N-Substituted Ureas and Thioureas in Biginelli Reaction Promoted by Chlorotrimethylsilane: Convenient Synthesis of N1-Alkyl-, N1-Aryl-, and N1,N3-Dialkyl-3,4-Dihydropyrimidin-2(1H)-(thi)ones
Sergey V. Ryabukhin, Andrey S. Plaskon, Eugeniy N. Ostapchuk, Dmitriy M. Volochnyuk*, Andrey A. Tolmachev
*Enamine Ltd, 23 A. Matrosova St, Kyiv, 01103, Ukraine, Email: D.Volochnyukenamine.net
S. V. Ryabukhin, A. S. Plaskon, E. N. Ostapchuk, D. M. Volochnyuk, A. A. Tolmachev, Synthesis, 2007, 417-427.
The classical Biginelli reaction has been extended by the use of N-substituted ureas and thioureas. N1-alkyl-, N1-aryl-, and N1,N3-dialkyl-3,4-dihydropyrimidin-2(1H)-(thi)ones were readily prepared in excellent yield using chlorotrimethylsilane in N,N-dimethylformamide as promoter and water scavenger.
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