Investigation the chemical reactivity of positions N3, C5 and C6methyl group in biginelli type compounds and synthesis of new dihydropyrimidine derivatives

The compounds 5ethoxycarbonyl1,6dimethyl43nitrophenyl3,4dihydropyrimidin2lHone 5 and 5ethoxycarbonyl1phenyl6methyl43nitrophenyl3,4dihydropyrimidin2lHone 1 were prepared by the Biginelli condensation method and they converted to eight N3 substituted dihydropyrimidines using NaH and various electrophiles ClCO2Et, TsCl, Ac2O, AcCl and PhCOCl. Compound 1 was monobrominated at the C6methyl group using bromine solution. Reaction of the bromo derivative with amino nucleophiles such as methyl amine and cyclohexyl amine produced two pyrrolopyrimidine derivatives. All the compounds except 5ethoxycarbonyl1phenyl6methyl43nitrophenyl3,4dihydropyrimidin2lHone 4 were purified by recrystallization methods. The structure of all the new compounds was confirmed using FTir,1H nmr, 13C nmr spectral and elemental analyses methods.