Subject Vilsmeier-Haack reaction

When (190) was subjected to a Friedel-Crafts reaction with benzoyl chloride, the result was an analog of coralyne with a phenyl rather than a methyl group at position 8. Kametani et al. (74YZ478) have carried out a parallel study using the Vilsmeier-Haack reaction to produce norcoralyne. 

Asokan et al. has developed a practical synthesis of 4-chloropyridines 1 from carbonyl compounds having two enolizable carbons adjacent to the carbonyl such as compound 2 <04T5069>. Ketone 2 was subjected to Vilsmeier-Haack reaction conditions leading to the... 

Subjecting acetanilides to the conditions of the Vilsmeier-Haack reactions is an effective method for the preparation of quinolines <8iJCS(Pi)i537>. On the other hand, if the phenacetanilide of anthranilic acid is subjected to the identical reaction conditions, 4-dimethylamino-3-phenyl-5H-benz[()]azepine-2,5-dione (189) is formed in high yield <84S349>. The phenyl group of anthranilic acid may be replaced by thienyl and pyridyl without loss in the efficiency of cyclization. 

A 4-bond synthesis of pyridines from carbonyl compounds, which were subjected to Vilsmeier-Haack conditions giving the conjugated iminium salts, has been achieved by reaction with ammonium acetate (Scheme 113)... 

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