109275-03-8Relevant articles and documents
Furopyridines. VI. Preparation and Reactions of 2- and 3- Substituted Furopyridines
Morita, Hiroyuki,Shiotani,Shunsaku
, p. 1465 - 1469 (2007/10/02)
This paper describes the synthesis and chemical properties of some 2- and 3-substituted furopyridines.Reaction of ethyl 2-chloronicotinate 1 with sodium ethoxycarbonylmethoxide or 1-ethoxycarbonyl-1-ethoxide gave β-keto ester 2 or ketone 5, respectively.Ketonic hydrolysis of 2 afforded ketone 3, from which furopyridine 4 was obtained by the method Sliwa.While, 2-methyl derivative 7 was prepared from 5 by reduction, O-acetylation and the subsequent pyrolysis.Reaction of ketone 3 with methyllithium gave tertiary alcohol 8 which was O-acetylated and pyrolyzed to give 3-methyl derivative 9.Formylation of 4, via lithio intermediate, with DMF yielded 2-formyl derivative 10, from which 7, was obtained by Wolff-Kishner reduction.Dehydration of the oxime 11 of 10 gave 2-cyano derivative 12, which was hydrolyzed to give 2-carboxylic acid 13.Reaction of 3-bromo compound 14 with copper(I)cyanide gave 3-cyano derivative 15.Alkaline hydrolysis of 15 afforded compound 16 and 17, while acidic hydrolysis gave carboxamide 18.Reduction of 15 with DIBAL-H afforded 3-formyl derivative 19.Wolff-Kishner reduction of 19 gave no reduction product 9 but hydrazone 20.Reduction of tosylhydrazone 21 with sodium borohydride in methanol afforded 3-methoxymethylfuropyridine 22.
