Novel Efficient and General Bromo-Decarboxylation Method

The invention idea is based on the conversion of cheap and widely-available carboxylic acids (feedstock chemicals) to valuable organic bromides[1], which are an integral part of Israel’s chemical industry.[2] The production of organic bromides proceeds typically from costly alcohols or related precursors, both domestically in Israel or abroad.[3] Thus, economical and environmentally benign approach to organo-bromine compounds will have positive industry-wide ramifications.

Bromodecarboxylation is a selective and attractive method for the synthesis of organic bromides. The synthesis of alkyl bromides from carboxylic acids has been known since 1939, with many different methods developed.[4] Although extensively deployed in research laboratories, they have found little foothold in industry. The reason is that all the existing methods are complicated, require expensive, oxygen and moisture sensitive[5], toxic[6] and highly-regulated chemicals (for instance by the FDA).

Here we present a new, extremely simple, efficient and metal-free bromodecarboxylation method. Our one-step protocol employs robust brominating agents, ambient conditions, and doesn’t require laborious product purification. The reaction is general: primary, secondary, tertiary alkyl bromides as well as aryl bromides can be prepared in high yields.

[1] Alexander Artaryan, Kseniya Kulbitski, Gennady Nisnevich, Mark Gandelman, US provisional application 62/238,197 and 62/238,208

[2] Jack W.Punkett, “Plunkett`s Chemicals, Coatings & Plastics Industry Almanac book”, 2009.

[3] Bromine Organic Compounds, “Kirk-Othmer Encyclopedia of Chemical Technology”, John Wiley and Sons, 2014.

[4] Hassner A., Namboothiri, I., “Organic Syntheses Based on Name Reactions - A Practical Guide to 750 Transformations”, Elsevier, 2012, p. 232.

[5] Johnson, R. G., Ingham, R. K. Chem. Rev. 1956, 56, 219-269.

[6] Cristol, S.J., Firth, W.C., J. Org. Chem., 1961, 26, 280.