Dimethylformamide → N-(5-formyl-pyridin-2-yl)-2,2-dimethyl-propionamide

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Reaction Conditions

Reaction Steps

A solution of N-(5-Bromo-pyridin-2-yl)-2,2-dimethyl-propionamide (8.7 g, Kelly, Tetrahedron Lett., 32, 1991, 4263) in THF (200 mL) was cooled to −70° C. under an argon atmosphere and treated dropwise over 30 minutes with n-butyllithium (45.78 mL, 1.6 M in hexane, Acros). The mixture was stirred 1 h at −70° C. and then treated dropwise (over 10 minutes, at −70° C.) with a mixture of N,N-dimethylformamide (5.25 mL) in THF (5 mL), and stirring was continued for further 30 minutes. The reaction mixture was then poured into 2M aqueous KHCO3 (1.2 L), tert-butyl methyl ether (1.2 L) was added, and after stirring for 20 minutes, the layers were separated, the organic layer extracted twice with tert-butyl methyl ether (total volume 0.3 L). The combined organic layers were dried over sodium sulphate, filtered and evaporated in vacuo to give N-(5-formyl-pyridin-2-yl)-2,2-dimethyl-propionamide (7 g) as an yellow oil that was used directly in the next step.

Provenance & Evidence