Synthesis 2010(21): 3615-3622  
DOI: 10.1055/s-0030-1258229
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Formation of 1,2-Dihydroquinoline-3-carboxylic Acid Derivatives from Methyl 3-(Arylamino)acrylates with Hydrogen Iodide

Shoji Matsumoto*, Takahiro Mori, Motohiro Akazome
Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoicho, Inageku, Chiba 263-8522, Japan
Fax: +81(43)2903401; e-Mail: smatsumo@faculty.chiba-u.jp;
Further Information

Publication History

Received 28 June 2010
Publication Date:
25 August 2010 (online)

Abstract

The reaction of methyl 3-(arylamino)acrylates with hydrogen iodide gave 1,2-dihydroquinoline-3-carboxylic acid derivatives at room temperature. This reaction proceeds efficiently in alcoholic solvent; bulky tert-butyl alcohol is the best solvent to give the 1,2-dihydroquinoline derivatives. It is particularly interesting that hydrogen iodide is the most efficient acid to achieve this reaction in tert-butyl alcohol. Various substituents at the phenyl ring are applicable. Compounds bearing meta-substituted phenyl ring with electron-donating group led to the corresponding 1,2-dihydroquinoline derivatives in good yields.

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MeO-5a can be converted to 5a in 86% yield by the reaction of MeO-5a with HI in MeCN.