N1- and N2-Substituted 2-Amino-5,6-dihydro-4(1H)-pyrimidinones (Heterocyclic Compounds, 79)

Article abstract of DOI:10.1007/BF00798460

The reactions of the monosubstituted guanidines 2b-h with methyl acrylate in dimethylformamide or ethanol as solvent preferentially afford 1-substituted 2-amino-5,6-dihydro-4(1H)-pyrimidinones 6b-h.The structures of 1-hexyl- and 1-benzyl-4-pyrimidinones 6c, e and of the picrate of 1-phenylpyrimidinone 6g were proved by comparison with authentic samples, which were prepared from N-substituted ethyl 3-amino-propionates 14c, e and g and cyanamide.Accordingly, 6g is not identical with authentic 2-phenylaminopyrimidinone 7g (prepared from 2-methylthio-4-pyrimidinone 10 and 2-thioxo-4-pyrimidinone 12 respectively, compare.N,N-Disubstituted guanidines 2i-m react with methyl acrylate in dimethylformamide as solvent to afford N²,N²-disubstituted 2-amino-5,6-dihydro-4-(1H)-pyrimidinones 7i-m.Action of morpholine-4-carboxamidine (2l) on methyl acrylate in ethanol yields 2-morpholinopyrimidinone 7l as byproduct and 3-ethoxy-N-propionamide (9l) as mainproduct.Keywords: Acrylic acid methylester, reactions; Guanidines, mono- and N,N-disubstituted; Propionamide, 3-ethoxy-N-; 4(1H)-Pyrimidinones, 2-amino; Pyrimidine-1-propionic acid ethylester, hexahydro-4-oxo-2-thioxo