Benzocaine → Ethyl 2-(3-bromophenyl)-4,4-dimethyl-1,2,3,4-tetrahydroquinoline-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-aminobenzoic acid ethyl ester (16.5 g, 100 mmol), 3-bromo benzaldehyde (18.5 g, 100 mmol) and ytterbium(III) triflate hydrate (12.4 g, 20 mmol) in acetonitrile (350 mL) was cooled to 0° C. in a sealed reaction bottle. Then a cooled solution of isobutene (28 g, 500 mmol) was added into. The reaction mixture was heated to 90° C. and stirred for 12 h. The solvent was removed in vacuo and the residue was purified on flash silica gel chromatography (silica gel from QingDao, 200-300 mesh, glass column from Shanghai SD company) (10% ethyl acetate/hexanes) to afford 2-(3-bromo-phenyl)-4,4-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester (16.7 g, 43%) as a white solid: MS (ESI) M+1=388.0.

Provenance & Evidence