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Preparation of 6‐, 7‐, and 8‐substituted derivatives of 2‐Oxa‐1,3,4,10‐tetraazacyclopenta[ b ]fluoren‐9‐one
Author(s) -
Bratton Larry D.,
Unangst Paul C.,
Rubin J. Ronald,
Trivedi Bharat K.
Publication year - 2001
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570380514
Subject(s) - chemistry , structural isomer , ninhydrin , diamine , stereochemistry , medicinal chemistry , organic chemistry , amino acid , biochemistry
The preparation of a variety of derivatives of 2‐oxa‐1,3,4,10‐tetraazacyclopenta[ b ]fluoren‐9‐one 1 is described. A series of substituted indan‐1‐ones were prepared and oxidized with N ‐bromosuccinimide and dimethyl sulfoxide to the corresponding ninhydrin derivatives. Cyclization of the ninhydrins with furazan‐3,4‐diamine yielded the target tetracycles. Appropiate choice of substituents in ninhydrins led to a preference for one regioisomer in the target tetracycles. This permitted the synthesis of a variety of 8‐substituted hetero‐cycles. In those instances where isomer formation was possible, structural assignments were confirmed by X‐ray crystallography.