Title:Synthesis and Crystal Structures of Some Pyridyl Aminothiazole and Thiazolidin-2-ylidene Benzamide Derivatives
Volume: 13
Issue: 4
Author(s): Reza Heydari, Fahimeh Shahrekipour and Claudia Graiff
Affiliation:
Keywords:
2-aminopyridine, 2-aminothiazole, 3-aminopyridine, benzoyl isothiocyanates, phenacyl bromide, thiazolidin-2-
ylidene benzamide.
Abstract: Background: Thiazoles and their derivatives are attracting continuing interest over the
years because of their varied biological activities. Thiazole and in particular the 2-amino thiazole moiety
has been incorporated into a wide variety of therapeutically interesting candidates including antibacterial,
anti-HIV, hypertension, anti-inflamenmatory, anti-viral and anticancer agents.
Methods: Several methods for the synthesis of thiazole derivatives have been developed. The most
widely used method being the Hantzch’s synthesis. In this paper, we describe an efficient one-pot method for the synthesis
of some thiazolidin-2-ylidene benzamide and aminothiazole derivatives via condensation of 3-aminopyridine or 2-
aminopyridine with phenacyl bromide and benzoyl isothiocyanates.
Results: The reaction of 3-aminopyridine, benzoyl isothiocyanates, and phenacyl bromide in the presence of triethylamine
yields thiazolidin-2-ylidene benzamides, which upon heating in acetic acid produce pyridyl aminothiazole derivatives.
Also the pyridyl aminothiazole derivatives were obtained by the reaction of 2-aminopyridine with benzoyl isothiocyanates
and phenacyl bromide in the presence of triethylamine. The molecular structures of the 4-chloro-N-(4-hydroxy-4-phenyl-
3-(pyridin-3-yl)thiazolidin-2-ylidene)benzamide, phenyl(4-phenyl-2-(pyridin-3-ylamino)thiazol-5-yl)methanone and (4-
phenyl-2-(pyridin-2-yl amino)thiazol-5-yl)(o-tolyl)methanone, have been fully determined by means of single crystal Xray
diffraction methods.
Conclusion: In summary, present study reports one-pot synthesis of thiazolidin-2-ylidene substituted benzamide and
pyridyl aminothiazole derivatives via condensation of 3-aminopyridine or 2-aminopyridine with phenacyl bromide and
substituted benzoyl isothiocyanates. The single crystal X-Ray diffraction analysis reveals unequivocally the exact identity
of the compounds.