Some reactions with ω-bromoacetophenone: Synthesis of Δαβ-butenolide and its transformation into pyrrole derivatives
✍ Scribed by Fathy M. Abdelrazek; Zaghloul E. Kandeel; Abdellatif M. Salah
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 280 KB
- Volume
- 6
- Category
- Article
- ISSN
- 1042-7163
No coin nor oath required. For personal study only.
✦ Synopsis
o-Bromoacetophenone reacts with the sodium salt of ethyl cyanoacetate to afford a-cyano-P-phenyl-A".Pbutenolide. This butenolide undergoes azo coupling with diazotized aromatic amines (ArNHJ to afford the hydrazo derivatives. These hydrazo derivatives (Ar= Ph, were transformed into the corresponding 3(2H)-pyridazinone derivatives on stirring in methanol in the presence of potassium hydroxide. These latter compounds were converted into the cowesponding 3-cyano-2,5-dihydroxy-4-phenyl-N-arylpyrrole derivatives on reduction with zinc dust in refluxing acetic acid, presumably via reductive cleavage of the N-N bond of the pyridazine followed by recyclization via loss of ammonia.