Accession Number:

ADA193951

Title:

Computational Study of 2-Aminopyrimidine, 2-Amino-5-Nitropyrimidine, and the Corresponding S,S-Dimethyl-N-Sulfilimines

Descriptive Note:

Journal article

Corporate Author:

NEW ORLEANS UNIV LA DEPT OF CHEMISTRY

Report Date:

1988-01-01

Pagination or Media Count:

7.0

Abstract:

In order to better understand why the formulation of sulfilimine intermediates facilitates the oxidation of some aminoazines, we have carried out a computational analysis of 2-aminopyrimidine II and S,S-dimethyl-N-2- pyrimidinylsulfilimine III. We also investigated a system for which the procedure fails 2-amino-5-nitropyrimidine VI and the corresponding sulfilimine VII. An ab initio SCF approach Gaussian 82 was used to compute the optimized structures and electrostatic potentials of these molecules. We found that the most negative regions in the sulfilimine intermediates as well as in the original aminoazines are associated with one or both of the ring nitrogens rather than the exocyclic one that is to be oxidized. An important new feature in the case of III is the development of extensive negative potentials above and below the ring plane, which make the exocyclic nitrogen much more accessible to electrophiles than it is in II. Thus the possibility of oxidation occurring at this site is significantly greater in III than in II. The presence of the electron-withdrawing nitrogen dioxide in VI presents the development of extensive, relatively strong negative regions above and below the ring accordingly there does not occur, in VII, an analogous increase in electrophilic accessibility to the exocyclic nitrogen.

Subject Categories:

  • Organic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE