Synlett

A novel and efficient lewis acid catalysed preparation of pyrimidines: Microwave-promoted reaction of urea and β-formyl enamides

…, M Borthakur, P Devi, CJ Saikia, A Saikia, U Bora…

文献索引：Saikia, Anil; Barthakur, Madan G.; Borthakur, Moyurima; Saikia, Chandan J.; Bora, Utpal; Boruah, Romesh C. Tetrahedron Letters, 2006 , vol. 47, # 1 p. 43 - 46

全文：HTML全文

被引用次数: 27

摘要

The 1 H NMR of 4a showed a singlet at δ = 8.28 for the aromatic proton of pyrimidine. The 13 C NMR spectra exhibited four characteristic signals for aromatic carbons at δ = 165.41, 165.35, 157.70 and 126.31. Similarly steroidal, acyclic and aliphatic formyl enamides 2b-h reacted with urea in the presence of samarium chloride to afford annelated pyrimidines 4b-h in high yields (Table [1] , entries 2-8). However, when the same reaction was carried out in refluxing ...