224314-08-3Relevant academic research and scientific papers
Microwave-enhanced synthesis of cyclic amidines
García, Ma Beatriz,Torres, Romina A.,Orelli, Liliana R.
, p. 4857 - 4859 (2007/10/03)
We present a simple and efficient microwave based protocol for the synthesis of heterocyclic amidines by PPE promoted cyclodehydration of N-aryl-N′-acylalkylenediamines. The method is general for five- to eight-membered heterocycles and affords high yield
Synthesis, NMR characterization and ab initio 6-31G* study of 1-Aryl-2,3-dialkyl-1,4,5,6-tetrahydropyrimidinium salts
Niemevz, Fernando,Link, Natalia P.,Perillo, Isabel A.,Orelli, Liliana R.
, p. 535 - 541 (2007/10/03)
We describe the synthesis of a series of 1-aryl-2,3-dialkyl-1,4,5,6- tetrahydropyrimdinium salts 1, by alkylation of the corresponding 1,4,5,6-tetrahydropyrimidines 2. We analyze the changes in the 1H and 13C NMR spectra of compounds 2 induced by protonation and quaternization. The results of an ab initio theoretical study on amidine 2a, and the cations resulting from its protonation (2aH+) and quaternization (1a+) are presented. A qualitative correlation was found between 13C NMR and theoretical data in the case of protonation. The influence of the substitution oatterns in the 1H and 13C NMR spectra of compounds 1 is also discussed.
Synthesis and properties of 1-aryl-2-alkyl-1,4,5,6- tetrahydropyrimidines
Orelli, Liliana R.,Niemevz, Fernando,Garcia, Maria B.,Perillo, Isabel A.
, p. 105 - 112 (2007/10/03)
A general method is described for the synthesis of 1-aryl-2-alkyl- 1,4,5,6-tetrahydropyrimidines 1, by cyclization of N-acyl-N'- aryltrimethylenediamines 2 with trimethylsilyl polyphosphate. Precursors 2 were obtained by aminolysis of the corresponding N-(3-bromopropyl)arnides 3. The 1H nmr spectra of tetrahydropyrimidines 1 are analyzed, discussing the influence of substituents in positions 1 and 2 of the heterocyclic ring. Alkaline hydrolysis of compounds 1, which originates exclusively N-acyl-N'- aryltrimethylenediamines 2, through an intermediate carbinolamine, was also studied. Cleavage of such an intermediate is discussed in the light of the stereoelectronic control theory. Reduction of compounds 1 with borane, leads regiospecifically to N-alkyl-N'-aryltrimethylenediamines 6.
