Synthesis of Quaternary Indoxyl Derivatives by Intramolecular Cyclization of Some Substituted Acetophenones

✍ Scribed by Ruiz, José R. ;Arán, Vicente J. ;Asensio, Juan L. ;Flores, María ;Stud, Manfred

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 665 KB
• Volume: 1994
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199419940708

✦ Synopsis

Abstract

The intramolecular cyclization of N,N‐disubstituted 2′‐halogenophenacylamine hydrobromides 1a–h to 1,1‐disubstituted 3‐oxoindolinium bromides 3a–f has been studied. Some 3‐oxoindolinium salts have also been prepared according to a different pattern by intramolecular cyclization of the phenacyl halides resulting from the bromination of 2′‐(dialkylamino)acetophenones 4 or from the treatment of 2′‐(dialkylamino)‐2‐diazoacetophenones 6a, b with hydrogen halides. Removal of hydrogen halide in salts 3a–g gives indolylio oxides 2a–g; these compounds have been shown to be unstable and decompose easily giving in general complex mixtures; only in the case of tetrahydroisoquinoline‐derived ylides 2e, g we have observed clear‐cut reactions leading, via a Stevens rearrangement followed by oxidation, to the 6,7‐dihydro‐13__H__‐indolo[2,1‐b][3]benzazepin‐13‐ones 8a, b. magnified image