Synthesis of 5-nitro-3,4-dihydropyrimidin-2(1H)-ones catalyzed by metal salts. Retro-Henry reaction with formation of N,N′-disubstituted ureas
摘要:
Three-component condensation of alpha-nitroacetophenone with aromatic aldehydes and urea in the presence of iron(III), cobalt(II), nickel(II), and copper(II) salts as catalyst led to the formation of 4,6-diaryl-5-nitro-3,4-dihydropyrimidin-2(1H)-ones and N-benzoyl-N'-(1-aryl-2-nitroethyl)ureas. The latter were formed as a result of retro-nitroaldol (retro-Henry) reaction of intermediate 4,6-diaryl-6-hydroxy-5-nitro-3,4,5,6-tetra-hydropyrimidin-2(1H)-ones.
Selective acylation of 5-nitro- and 5-ethoxycarbonyl-4,6-diaryl-3,4-dihydropyrimidin-2(1H)-ones
作者:V. F. Sedova、O. P. Shkurko
DOI:10.1134/s1070428010110163
日期:2010.11
The acetylation and chloroacetylation of 5-nitro- and 5-ethoxycarbonyl-substituted 4,6-diaryl-3,4-dihydropyrimidin-2(1H)-ones proceeds regioselectively at the N3 atom of the heterocycle whereas the acetylation of the 5-aryloxy-substituted analog results in a mixture of N1- and N3-acetylated regioisomers.