2,4,6-Trichlorobenzoyl chloride explained

2,4,6-Trichlorobenzoyl chloride or Yamaguchi's reagent is an chlorinated aromatic compound that is commonly used in a variety of organic syntheses.^{[1] [2]}

Yamaguchi esterification

It is the primary reactant in Yamaguchi esterification. 2,4,6-Trichlorobenzoyl chloride readily reacts with alcohols. This newly formed reagent, when mixed with a stoichiometric amount of 4-dimethylaminopyridine, cyclizes and forms esters. This reaction creates 2,4,6-trichlorobenzoic acid as a byproduct.

Preparation

2,4,6-Trichlorobenzoyl chloride is prepared by reacting 2,4,6-trichloroaniline with N-butyllithium in a carbon dioxide atmosphere. This produces 2,4,6-trichlorobenzoic acid, which can then be refluxed in thionyl chloride to form 2,4,6-trichlorobenzoyl chloride.^[3] Since 2,4,6-trichlorobenzoic acid is produced as a by product of the esterification process, it can be refluxed again to recreate 2,4,6-trichlorobenzoyl chloride.

References

1. Fürstner . Alois . Fasching . Bernhard . O'Neil . Gregory W. . Fenster . Michaël D. B. . Godbout . Cédrickx . Ceccon . Julien . 2007 . Toward the total synthesis of spirastrellolide A. Part 3: Intelligence gathering and preparation of a ring-expanded analogue . Chem. Commun. . en . 29 . 3045–3047 . 10.1039/B707835H . 17639136 . 1359-7345.
2. Book: Category 3, Compounds with Four and Three Carbon Heteroatom Bonds: Three Carbon—Heteroatom Bonds: Esters, and Lactones; Peroxy Acids and R(CO)OX Compounds; R(CO)X, X=S, Se, Te . 2007 . Georg Thieme Verlag . 978-3-13-144691-6 . Panek . J. S. . Stuttgart . en . 10.1055/sos-sd-020-01369.
3. Kotammagari . Tharun . 2014-04-28 . 2,4,6-Trichlorobenzoyl Chloride (Yamaguchi Reagent) . Synlett . en . 25 . 9 . 1335–1336 . 10.1055/s-0033-1341245 . 0936-5214. free .