Short and Efficient Synthesis of Oxazinone- and Thiazinone-Containing Bicyclic Heteroaromatic Aldehydes

Abstract

Short and efficient route for the synthesis of oxazinone- and thiazinone-containing bicyclic heteroaromatic aldehydes, which involves the key step of palladium-catalyzed reductive carbonylation, is described. Overall routes for the synthesis of these aldehydes are short, versatile, and scalable with good yields of the product.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]

GRAPHICAL ABSTRACT

Keywords:

• Benzoxazinone
• bicyclic aldehydes
• carbonylation
• pyridoxazinone

ACKNOWLEDGMENTS

We deeply acknowledge the analytical support provided by Suresh Rudrapatna, Sandesh Jatheendranath, and Sreenivasaiah Menasinkai. We also thank Eknath Bellale for proofreading this article.

Notes

^a Isolated yields after column purification.

^b Mixture of compounds 2a and 6.

^c Only debrominated product 6.