A pyrrolopyrimidine was required in 100 Kg quantities for pharmaceutical development.  This required preparation of an acetylaminobutanone intermediate which could be obtained easily in the laboratory by treatment of alanine with acetic anhydride and pyridine – the Dakin-West procedure.¹ However, this procedure could not be used safely on a technical scale because of the sudden evolution of a stoichiometric amount of carbon dioxide in the decarboxylation step.  The chemists at Novartis AG developed a procedure that utilized DMAP and TEA² with additional acetic acid to provide water to promote azlactone hydrolysis and facilitate decarboxylation. Alanine was added as the limiting reagent to control carbon dioxide evolution.  The result was formation of acetylaminobutanone safely (50 Kg in a 400 L reactor) in greater than 90% yield, with great reduction in the amount of acetic anhydride used.³

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1. Buchanan, G. L. Chem. Soc. Rev. 1988, 17, 91
2. Hoefle, G.; Prox, A.; and Steglich, W. Chem. Ber. 1972, 105, 1718.
3. Fischer, R. W.; Misun, M. Org. Proc. Res. Dev. 2001, 5, 581