Molecular structure of 5-chloro-2-[p-t-butylphenyl]benzoxazole. Relation between structure and antimicrobial activity of 2,5-disubstituted benzoxazoles

Mrozek A., Trzezwinska H., Karolak-Wojciechowska J., Yalcin I., Sener E.

POLISH JOURNAL OF CHEMISTRY, vol.73, no.4, pp.625-633, 1999 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 73 Issue: 4
  • Publication Date: 1999
  • Journal Name: POLISH JOURNAL OF CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED)
  • Page Numbers: pp.625-633
  • Keywords: molecular structure, semiempirical calculations, bond length, biological activity
  • Ankara University Affiliated: No

Abstract

As part of our investigation on antimicrobial agents, the structure of 5-chloro-2- [p-t-butylphenyl]benzoxazole is reported: C17H16ClNO, mel. mass 285.77, monoclinic, space group: C2/c; a = 32.164(6) Angstrom, b = 6.756(1) Angstrom, c = 13.710(3) Angstrom; beta = 92.73(3)degrees; V= 2975.8(10) Angstrom(3); and, = 1.276 g cm(-3); Z = 8; F(000) = 1200; mu(CuKalpha)= 2.219 mm(-1). Final R = 0.0658 for 2621 reflections with F > 4 sigma(F). Final atomic coordinates for this 2,5-disubstituted benzoxazole were used as a starting point in molecular modelling of remaining 32 derivatives searched as antimicrobial agents. Electronic parameters calculated with quantum chemistry methods and classical Hansch's constants were applied in searching for structure-activity correlation. It was established that geometrical para meters (area and volume) and LUMO energy values seem to be most important for the activity.