title: Indolizines and pyrrolo[1,2-c]pyrimidines decorated with a pyrimidine and a pyridine unit respectively.
abstract: The three possible structural isomers of 4-(pyridyl)pyrimidine were employed for the synthesis of new pyrrolo[1,2-c]pyrimidines and new indolizines, by 1,3-dipolar cycloaddition reaction of their corresponding N-ylides generated in situ from their corresponding cycloimmonium bromides. In the case of 4-(3-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine the quaternization reactions occur as expected at the pyridine nitrogen atom leading to pyridinium bromides and consequently to new indolizines via the corresponding pyridinium N-ylides. However, in the case of 4-(2-pyridyl)pyrimidine the steric hindrance directs the reaction to the pyrimidinium N-ylides and, subsequently, to the formation of the pyrrolo[1,2-c]pyrimidines. The new pyrrolo[1,2-c]pyrimidines and the new indolizines were structurally characterized through NMR spectroscopy. The X-ray structures of two of the starting materials, 4-(2-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine, are also reported.
authors.affiliation: Center for Organic Chemistry C.D. Nenitzescu, Romanian Academy, Spl. Independentei 202B, Bucharest 060023, Romania ; Faculty of Applied Chemistry and Materials Science, 'Politehnica' University of Bucharest, Polizu Street 1-7, 011061 Bucharest, Romania.
authors.forename: Marcel Mirel
authors.initials: MM
authors.lastname: Popa
authors.affiliation: Research Center Oltchim, Str. Uzinei 1, RO 240050, Ramnicu Valcea, Romania.
authors.forename: Emilian
authors.initials: E
authors.lastname: Georgescu
authors.affiliation: Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.
authors.forename: Mino R
authors.initials: MR
authors.lastname: Caira
authors.affiliation: Research Dept., Teso Spec SRL, Str. Muncii 53, RO-915200 Fundulea, Calarasi, Romania.
authors.forename: Florentina
authors.initials: F
authors.lastname: Georgescu
authors.affiliation: Center for Organic Chemistry C.D. Nenitzescu, Romanian Academy, Spl. Independentei 202B, Bucharest 060023, Romania.
authors.forename: Constantin
authors.initials: C
authors.lastname: Draghici
authors.affiliation: Faculty of Applied Chemistry and Materials Science, 'Politehnica' University of Bucharest, Polizu Street 1-7, 011061 Bucharest, Romania.
authors.forename: Raluca
authors.initials: R
authors.lastname: Stan
authors.affiliation: Center for Organic Chemistry C.D. Nenitzescu, Romanian Academy, Spl. Independentei 202B, Bucharest 060023, Romania.
authors.forename: Calin
authors.initials: C
authors.lastname: Deleanu
authors.affiliation: Center for Organic Chemistry C.D. Nenitzescu, Romanian Academy, Spl. Independentei 202B, Bucharest 060023, Romania.
authors.forename: Florea
authors.initials: F
authors.lastname: Dumitrascu
keywords: 4-pyridylpyrimidine; N-ylide; indolizine; nitrogen heterocycles; pyrrolo[1,2-c]pyrimidine