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Eine einfache Synthese für 2‐Aminomethyl‐indene. 11. Mitteilung über metallorganische Reaktionen and Folgeprodukte
Author(s) -
Marxer Adrian
Publication year - 1982
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19820650142
Subject(s) - chemistry , benzyl alcohol , indene , yield (engineering) , ring (chemistry) , ketone , acetic acid , alcohol , medicinal chemistry , sulfuric acid , organic chemistry , catalysis , materials science , metallurgy
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%).