Synthesis and study of 1,4,5,6-tetrahydropyrimidines with disymmetrical N-aryl substituents

L. R. ORELLI, M. B. GARCÍA, I. A. PERILLO

Viena, Austria

Congreso; XVII International Congress of Heterocyclic Chemistry; 1999

SYNTHESIS AND STUDY OF 1,4,5,6-TETRAHYDROPYRIMIDINES WITH DISYMMETRICAL N-ARYL SUBSTITUENTS   Liliana R. Orelli, M. Beatriz García and Isabel A. Perillo   Departamento de Química Orgánica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 (1113), Buenos Aires, Argentina.   The synthesis of diversely substituted 1,4,5,6-tetrahydropyrimidines is a subject of interest due to the pharmacological activity presented by some members.  Typically, such properties arise from the affinity of the cyclic amidine system for several types of acetylcholine receptors. In previous work we studied the dynamic stereochemistry of diversely substituted 1-aryl-1,4,5,6-tetrahydropyrimidines with symmetrical N-aryl substituents.  In the present communication we present the synthesis and stereochemical study of some tetrahydropyrimidine derivatives bearing disymmetrical N-aryl substituents.  As a consequence of the rotameric behavior of the N-aryl moiety, some of these compounds display axial chirality.  Stereochemical and conformational features of tetrahydropyrimidines 1 are discussed on the on the basis of NMR spectral data.     [a]: RCOCl or (RCO)2/OH-; [b]: 2ArNH2, 120ºC; [c]: RCOCl or (RCO)2/OH-; [d]: trimethylsilyl polyphosphate   Compounds 1,2 Ar R a 2-CH3 C6H4 ter-C4H9 b 2-CH3 C6H4 C6H5 c b-C10H7 ter-C4H9 d b-C10H7 C6H5 e 2-NO2 C6H4 iso-C3H7 g 2-NO2 C6H4 ter-C4H9