[4 + 2] Cycloaddition Reactions Involving 2-Arylmethylidene-1-thiooxoindan Intermediates and Antimicrobial Activity Evaluation of Some Products

Abstract

2-(4-Fluorophenyl)methylidene-1-thiooxoindane-, 2-(4-methoxyphenyl) methylidene-1-thiooxoindane-, 2-(4-N,N-dimethyaminophenyl)methylidene-1-thiooxoindane dimers 5a–c were prepared by the reaction of the corresponding α,β -unsaturated ketones 3a–c with Lawesson' Reagent (LR) in refluxing benzene. When these dimers were refluxed with LR in xylene, the 1,2-thiaphospholene-2-sulfides 7a–c were obtained. On the other hand, the thermolysis of the dimers 5a–c in the presence of acrylamide or dichloromaleic anhydride gave the corresponding cycloadducts of Diels-Alder type 8a–c, and 10a–c, respectively. The 3-carbamoyl thiapyran derivatives 8a–c showed good antimicrobial activity.

Keywords:

• Antimicrobial activity
• 2-arylmethylidene-1-thiooxoindane dimers
• Diels–Alder cycloadducts
• Lawesson's reagent
• 1,2-thiaphospholene-2-sulfides
• α, β-unsaturated ketones

The authors would like to thank Dr. Hassan M. Awad, Natural and Microbial Products Department, National Research Centre, for the evaluation of the antimicrobial activity.