FORMATION OF HYDROGEN-BONDING ADDUCT BETWEEN 1-PHENYL-2-AMINO PYRIMIDINE AND VANILINE, C17H13N3O2

The adduct compound was prepared by condensation of equimolar quantiti es of analar vaniline and 1-phenyl-2-amino pyrimidine in absolute ethy l alcohol. Prismatic crystals were obtained with the crystallographic data: a = 12.901 (6), b = 19.297 (9), c = 6.828 (3)angstrom, gamma = 1 02.67 (2)degrees, V= 1657.9 Z = 4, F.W. = 291.31, D(x) = 1.17 g/cm3, s pace group P2/n, R = 0.038 and R(w) = 0.036. The intensity data were c ollected on an Enraf Nonius CAD-4 computer controlled diffractometer u sing MoKalpha radiation. The structure was solved by direct method and refined by full matrix least-squares using anisotropic temperature fa ctor of all atoms, except for hydrogen ones, which were treated isotro pically. A full discussion was given to explain: a) the occurrence of the condensation process between the OH-group of vaniline and the hete rocyclic N-atom in position 5 of the pyrimidine cycle and b) why this condensation does not take place between the amino-group of the pyrimi dine compound and the aldehydic group of vaniline to give a Schiff bas e.