Benzocaine → Ethyl 4-(methylamino)benzoate

Participants

Reaction Steps

A mixture of ethyl p-aminobenzoate (25.2 g), triethyl orthoformate (80 g) and trifluoroacetic acid (0.2 mL) is refluxed under heating for 3 hours. After cooling, the reaction mixture is concentrated in vacuo and the residue is subjected to azeotropic distillation with ethanol. The residue is suspended in ethanol (400 mL) and thereto is added sodium borohydride (23 g), and the mixture is refluxed under heating for 3 hours. After cooling, to the reaction mixture is added ethyl acetate and water. The mixture is stirred at room temperature for 1 day. The organic layer is separated, dried over anhydrous sodium sulfate, and concentrated in vacuo. The residue is purified by flash column chromatography on silica gel (Solvent; n-hexane:ethyl acetate=4:1) to give ethyl 4-(methylamino)benzoate (12.7 g, yield; 46%) as a pale yellow amorphous powder. MS (APCI) m/z: 180 [M+H]+

Provenance & Evidence