Efficient Synthesis of 1-Amino-2-naphthalenecarboxylic Acid Derivatives via a Sequential Michael Addition/Enolate−Nitrile Coupling Route and Its Application to Facile Preparation of 9-Amino Analogues of Arylnaphthofuranone Lignans

Autor:	Keiichiro Takada, Taichi Kitamura, Hideo Tanaka, Kazuhiro Kobayashi, Tomokazu Uneda, Osamu Morikawa, Hisatoshi Konishi
Rok vydání:	1997
Předmět:	chemistry.chemical_classification Nitrile Carboxylic acid Organic Chemistry chemistry.chemical_element Diglyme Zinc chemistry.chemical_compound chemistry Intramolecular force Michael reaction Organic chemistry Dehydrogenation Palladium
Zdroj:	The Journal of Organic Chemistry. 62:664-668
ISSN:	1520-6904 0022-3263
DOI:	10.1021/jo961744r
Popis:	The reaction of 2-(alpha-lithioalkyl)benzonitriles, generated in situ by treatment of 2-alkylbenzonitriles with LDA in diglyme, with alpha,beta-unsaturated carboxylates and nitriles produced 1-amino-3,4-dihydro-2-naphthalenecarboxylates and carbonitriles in 54-98% yields through Michael addition of the lithio nitriles to alpha,beta-unsaturated carboxylic acid derivatives, followed by zinc iodide-promoted intramolecular enolate-nitrile coupling of the resulting enolate intermediates. The dihydronaphthalenecarboxylic acid derivatives were converted to the corresponding 1-amino-2-naphthalenecarboxylic acid derivatives in 43-99% yields on dehydrogenation with palladium on activated carbon in refluxing p-cymene. Subsequently, we showed that, by using a similar reaction sequence, 9-amino analogues of arylnaphthofuranone lignan derivatives {9-amino-4-arylnaphtho[2,3-c]furan-1(3H)-ones} could also be prepared from 2-(arylmethyl)benzonitriles and furan-2(5H)-one in good overall yields (59-61%).
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9aa4c3add3b558de36e5e8973d03b4d0 https://doi.org/10.1021/jo961744r Zobrazit plný text záznamu