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A New Synthesis of Benzo[ f ]isoindole‐4,9‐diones by Radical Alkylation and Bromomethylation of 1,4‐Naphthoquinones
Author(s) -
Deblander Jurgen,
Van Aeken Sam,
Jacobs Jan,
De Kimpe Norbert,
Abbaspour Tehrani Kourosch
Publication year - 2009
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200900562
Subject(s) - isoindole , chemistry , alkylation , reductive amination , amination , halogenation , decarboxylation , stereochemistry , hydrazone , combinatorial chemistry , organic chemistry , catalysis
Two synthetic routes towards substituted benzo[ f ]isoindole‐4,9‐diones have been developed. One strategy relies on the synthesis of N ‐trifluoroacetyl‐protected 2‐(1‐aminoalkyl)‐1,4‐naphthoquinones starting from 1,4‐naphthoquinone and N ‐trifluoroacetyl‐α‐amino acids by a Kochi–Anderson oxidative decarboxylation method. Furthermore, it was demonstrated that 2‐(1‐aminoalkyl)‐1,4‐naphthoquinones are suitable precursors for the synthesis of 1‐alkylbenzo[ f ]isoindole‐4,9‐diones by bromomethylation and subsequent N ‐deprotection. Further functionalization by N ‐alkylation and bromination resulted in completely and asymmetrically substituted benzo[ f ]isoindole‐4,9‐diones. The second synthesis is based on a reductive amination of 3‐(bromomethyl)‐1,4‐dimethoxynaphthalene‐2‐carbaldehyde and subsequent oxidation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)