The Reactions of Hydrochlorides of 2, 3-Tri(Tetra) Methylene-3, 4-Dihydropyrimidine-4-Ones with N-Bromosuccinimide and Bromine

摘要

Aims: To carry out reactions between hydrochlorides of 2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones and N-bromosuccinimide (and/or bromine), to determine way of reactions.Study Design: Official design.Place and Duration of Study: Department of Organic Chemistry, Institute of the Chemistry of Plant Substances (ICPS) between January 2012 and September 2013.Methodology: We have synthesized 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones from ethyl β-aminocrotonate and γ-butyro- or δ-valerolactames in the presence of different agents, such as D?D?l_(5), POCl_(3) and SOCl_(2). For convenient operations the oily bases of 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones have been transmuted into the appropriate hydrochlorides. Bromination by equimolar amount of hydrochlorides with N-bromosuccinimide at room temperature in water gives 5-bromo-6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones. Treatment of them by bromine resulted in the formation of perbromides. The reactions were monitored and controlled by TLC. Bromine-products were characterized by IR, ~(1)H NMR, mass-spectra determinations and chemical transformation.Results: Electrophilic substitution at C5 atom was successfully carried out when we have used N-bromosuccinimide. Perbromides of 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones were produced when we have used bromine. Perbromides performed to hydrobromides and bromine complexes when we have treatment of them by acetone and NaHCO_(3) solution respectively.Conclusion: Bromination of hydrochlorides of 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones by N-bromosuccinimide gives 5-bromine-derivatives. Bromination of them by bromine followed to the formation of perbromides of 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones which are performed to hydrobromides and bromine complexes when we have used corresponding treatments.