Eine einfache Synthese für 2-Aminomethyl-indene. 11. Mitteilung über metallorganische Reaktionen and Folgeprodukte

✍ Scribed by Adrian Marxer

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: German
• Weight: 465 KB
• Volume: 65
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19820650142

✦ Synopsis

Abstract

To obtain the title compounds 1‐aminomethyl‐substituted α‐vinyl‐benzyl alcohols of type 13 are treated with concentrated sulfuric acid in acetic or propionic acid containing small amounts of their anhydrides to give aminomethyl ‐ indenes in excellent yield. Depending on the benzyl alcohols used, the new indenes are substituted at C(2) by an aminomethyl group, and at C(3) by various substituents, examples of which are given in Table 3, according to R in the benzyl alcohols of Table 1. To obtain a ring closure, the benzyl alcohol 13 must at least contain one free ortho position.

The starting benzyl alcohols are easily obtainable by Grignard reaction, e.g. from 2‐bromo‐3‐(dimethylamino)‐l‐propen, originally detected by Normant et al. [7], and various ketones.

If a tricyclic ketone is used, benzyl alcohols of types 19, 20 and 21 (Table 2) are obtained in excellent yields. From these, ring closures lead to tetracyclic compounds of types 22, 23 and 24 (Table 4) but in lower yields (13‐42%).