Formation of Aryl [1-Cyano-4-(dialkylamino)butadienyl] Ketones from Pyridines

Abstract

Treatment of 2-chloropyridine with LDA and the Weinreb amide of benzoic acid afforded three unusual products, namely N-methylbenzamide, 2-chloropyridine-3-methanol, and the ring-opened addition product. This same final product could also be obtained from 2-chloro-3-benzoylpyridine on treatment with LDA. Mechanistic insight for the formation of these products is provided.

Key words

pyridines - Weinreb amides - LDA - pyridine ring-openings - anions

• References

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The formation of this anion is precedented in the literature:
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• 8b We thank Dr. Saeed Khan for carrying out the single crystal X-ray determination.