Synthesis and Characterization of Some Nitrosubstituted 3,5-Diaryl Isoxazolines, Thioisoxazolines and their Derivatives

Abstract

Chalcones (IIIa-d) or flavanones (IVa-d) were reacted with ethanol, hydroxylamine hydrochloride and aqueous KOH to give isoxazoline (Va-d). Isoxazoline (Va-d) and P₂S₅ was refluxed with pyridine to give thioisoxazoline (VIa-d). Isoxazoline (Va-d) was reacted with acetic anhydride and a pinch of anhydrous sodium acetate to give 3-(2-acetoxy)-isoxazoline (VIIa-d). Thioisoxazoline (VIa-d) was reacted with acetic anhydride in presence of anhydrous sodium acetate to give 3-(2-acetoxy)-thioisoxazoline (VIIIa-d).