Synthesis of [3,3′(4H,4′H)‐Bi‐2H‐1,3‐oxazine]‐4,4′‐diones and Their Hydrolysis

Abstract

The [3,3′(4H,4′H)‐bi‐2H‐1,3‐oxazine]‐4,4′‐diones 3a–3i were obtained by [2+4] cycloaddition reactions of furan‐2,3‐diones 1a–1c with aromatic aldazines 2a–2d (Scheme 1). So, new derivatives of bi‐2H‐1,3‐oxazines and their hydrolysis products, 3,5‐diaryl‐1H‐pyrazoles 4a–4c (Scheme 3), which are potential biologically active compounds, were synthesized for the first time.