72361-90-1Relevant articles and documents
A novel one-step synthesis of quinolinium salts and 4-quinolones from formanilides
Meth-Cohn, Otto,Taylor, David L.
, p. 3629 - 3632 (1993)
N-Methylformanilide in POCl3 reacts readily at 80°C with alkanoamides(RCH2CONR′2) to give 3-R-4-chloroquinolinium salts in good yields. The arylamide reacts as its Vilsmeier salt and the alkanoamide as an α-chloroenamine. High yields of 4-quinolones are easily obtained by base treatment.
The Reverse Vilsmeier Approach to the Synthesis of Quinolines, Quinolinium Salts and Quinolones
Meth-Cohn, Otto,Taylor, David L.
, p. 12869 - 12882 (2007/10/02)
N-Methylformanilide (MFA) reacts with various electron-rich alkenes in POCl3 solution to give N-methylquinolinium salts generally in good yield.The alkenes can be vinyl acetate, an aldehyde or ketone enamine (preferably the morpholine enamine), a methyl aryl ketone (reacting as its enol) or it may be generated from an alkanoamide bearing α-protons (which produces an α-chloroenamine in situ).The reaction is effective for a variety of other alkyl-, aryl- and benzyl-formanilides as well as ring substituted anilides though electron-withdrawing groups tend to inhibit cyclisation.The mechanism of the cyclisation has been elucidated and shown to involve an electrophilic ?6s process.The reactions of MFA with amides in POCl3 gives 4-quinolones on alkaline workup.
