Investigation the chemical reactivity of positions N-3, C-5 and C6-methyl group in biginelli type compounds and synthesis of new dihydropyrimidine derivatives

✍ Scribed by Y. R. Mirzaei; H. Azamat; H. Namazi

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2001
• Tongue: English
• Weight: 45 KB
• Volume: 38
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570380507

✦ Synopsis

Abstract

The compounds 5‐ethoxycarbonyl‐1,6‐dimethyl‐4‐(3‐nitrophenyl)‐3,4‐dihydropyrimidin‐2(l__H__)‐one (5) and 5‐ethoxycarbonyl‐1‐phenyl‐6‐methyl‐4‐(3‐nitrophenyl)‐3,4‐dihydropyrimidin‐2(l__H__)‐one (1) were prepared by the Biginelli condensation method and they converted to eight N‐3 substituted dihydropyrimidines using NaH and various electrophiles (ClCO~2~Et, TsCl, Ac~2~O, AcCl and PhCOCl). Compound (1) was mono‐brominated at the C~6~‐methyl group using bromine solution. Reaction of the bromo derivative with amino nucleophiles such as methyl amine and cyclohexyl amine produced two pyrrolo‐pyrimidine derivatives. All the compounds except 5‐ethoxycarbonyl‐1‐phenyl‐6‐methyl‐4‐(3‐nitrophenyl)‐3,4‐dihydropyrimidin‐2(l~H~)‐one (4) were purified by recrystallization methods. The structure of all the new compounds was confirmed using FT‐ir,^1^H nmr, ^13^C nmr spectral and elemental analyses methods.