Comparison of the reactivities of 2-mercaptoaniline and 2-hydroxyaniline with 2-chloronicotinoyl chloride

Abstract

The reaction between equimolar 2-chloronicotinoyl chloride and 2-mercaptopyridine in ClCH₂CH₂Cl, after 30 minutes refluxing in ClCH₂CH₂Cl solution, produced pyrido[2,3,b][1,5]benzothiazepin-5(H)one 7, and 6-[3-(2-benzothiazolyl)pyridin-2-yl)thio]-N-[3-(2-benzothiazolyl)pyridin-2-yl]aniline 8. In contrast, the reaction using the same reaction conditions between equimolar 2-chloronico- tinoyl chloride and 2-hydroxypyridine, produced the simple amide, 2-chloro-N-(2-hydroxyphenyl) nicotinamide 9. 2-Chloro-N-(2-mercaptophenyl)nicotinamide was considered to be a common intermediate in the formation of 7 and 8. The characterizations of 7–9 were achieved by X-ray crystallography. The conformations of 7 and 8 in the solid state can be described as “U” and “V”-shaped, respectively.

Keywords:

• 2-Benzothiazolyl derivatives
• 2-Chloronicotinoyl chloride
• X-ray crystallography
• Pyrido[2,3,b][1,5]benzothiazepin-5(H)one

Acknowledgements

JLW acknowledges support by CNPq, Brazil. The authors thank the EPSRC X-ray Crystallographic Service, University of Southampton, England for the data collections.