Tetrahydrofuran → Methyl 2-(3-(benzyloxycarbonyl)phenyl)-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-8-carboxylate

Participants

Reaction Steps

To a mixture of methyl 2-aminobenzoate (0.77 g, 5.1 mmol) and benzyl 3-formylbenzoate (1.23 g, 5.1 mmol) in tetrahydrofuran (20.5 mL) was added isobutyl aldehyde (0.48 g, 6.68 mmol), followed by yttrium(III) trifluoromethanesulfonate (159 mg, 0.26 mmol), the reaction mixture was stirred at room temperature under nitrogen atmosphere for 23 h, Thin layer chromatography (petroleum ether:ethyl acetate=10:1) showed the reaction was nearly complete. The reaction was quenched by brine and separated. The aqueous layer was extracted with Ethyl acetate (twice) and the combined organic layers were washed with brine, dried over anhydrous magnesium sulfate. Removal of the solvent in vacuo and the residue was purified by column chromatography (petroleum ether:ethyl acetate=20:1) to afford 0.66 g of methyl 2-(3-(benzyloxycarbonyl)phenyl)-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-8-carboxylate as a yellow oil, which was used in next step without further purification.

Provenance & Evidence