Diethylamine → N,N-diethyl-4-formylbenzamide

Participants

Reaction Conditions

Reaction Steps

To a 12 L flask equipped with mechanical stirrer and cold bath was charged 300 g (2 mol) of 4-carboxybenzaldehyde, 4.5 L of tetrahydrofuran and 245 g (2.4 mol) of triethylamine. This solution was cooled to −4° C. with methanol/ice bath. To the reaction was charged 236 g (1.9 mol) of pivaloyl chloride at a rate that maintained the temperature below 5° C. After stirring for 2 h the resulting slurry was filtered and the filter cake was washed with 1 L of THF. The filtrates were returned to the reactor and cooled below −5° C. Diethylamine (438 g, 6 mol) was slowly added maintaining the temperature below 0° C. The reaction was stirred for several hours and allowed to warm. The solvent was then removed under vacuum and the resulting residue was dissolved in 2 L of ethyl acetate. The resulting solution was washed with 1 L of water and the aqueous layer was back-extracted with 2×500 mL ethyl acetate. The combined organic layer was washed with 3×500 mL of 1 N HCl and 3×500 mL of NaHCO3 (aq, sat). This solution was dried with Na2SO4 and the solvent was removed under vacuum to give a golden brown oil (172 g, 85%) containing ˜13% impurity by NMR. The aldehyde was used with out further purification.

Provenance & Evidence