Triethylamine → N-(4-Carboxybenzyl)cinnamamide

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Reaction Steps

1,1'-Carbonyldiimidazole (3.71 g) is added to an ice-cold stirred solution of cinnamic acid (3.13 g) in 30 mL tetrahydrofuran. After stirring for an additional 1 hr, methyl 4-(aminomethyl)benzoate hydrochloride (4.7 g) and triethylamine (3.23 mL) are added and the final mixture stirred while immersed in an ice water bath for an additional 30 min, followed by stirring overnight at room temperature. After removal of the solvent by rotary evaporation, the residue is taken up in chloroform (250 mL) and extracted with water (200 mL), 1N HCl (3×50 mL), water 100 mL), saturated sodium bicarbonate (100 mL), brine (100 mL) and the final chloroform layer dried over anhydrous magnesium sulfate. After evaporation of the solvent in vacuo, the crude product (2.74 g) is suspended in 100 mL tetrahydrofuran and 20 mL 2N NaOH and the mixture stirred at room temperature overnight. The mixture is then made acidic by addition of excess 1N HCl, and the precipitate recovered by filtration. After washing the filter cake with water and pressing to remove as much water as possible, the white solid is crystallized from methanol/2N HCl as N-(4-carboxybenzyl)cinnamamide, m.p. 238°-239° C.

Provenance & Evidence