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A novel synthesis of indole derivatives by the reaction of N ‐arylhydroxamic acids with malononitrile
Author(s) -
Tomioka Yukihiko,
Ohkubo Kimiko,
Maruoka Hiroshi
Publication year - 2007
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.5570440222
Subject(s) - malononitrile , chemistry , triethylamine , sodium methoxide , cyanoacetamide , indole test , intramolecular force , medicinal chemistry , base (topology) , organic chemistry , methanol , catalysis , mathematical analysis , mathematics
An approach to indole derivatives from N ‐arylhydroxamic acids and malononitrile via a [3,3]‐sigmatropic rearrangement and intramolecular cyclization is described. Reactions of N ‐arylhydroxamic acids 1a‐c, 2a‐c and 3a‐c with malononitrile in the presence of triethylamine at room temperature gave the corresponding α‐cyanoacetamide derivatives 4a‐c, 5a‐c, 6a‐c, 7a‐c and 8a‐c . Thermal treatment of 4a‐c, 5a‐c and 7a‐c with a base, e.g. triethylamine and sodium methoxide, caused intramolecular cyclization and deacylation to afford the corresponding indole derivatives 9‐11 .