Cesium carbonate → Methyl 2-isobutyl-5-[4-(methylsulfonyl)phenoxy]-1-oxo-1,2,3,4-tetrahydroisoquinoline-7-carboxylate

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Reaction Conditions

Reaction Steps

A mixture of methyl 5-hydroxy-2-isobutyl-1-oxo-1,2,3,4-tetrahydroisoquinoline-7-carboxylate (250 mg, 0.90 mmol), 4-fluorophenyl methyl sulfone (236 mg, 1.35 mmol), Cs2CO3 (441 mg, 1.35 mmol) and CuI (100 mg, 1 mmol) in DMF (20 mL) was heated to 100° C. for 4 hours. The solvent was removed under reduced pressure. The residue was poured into water (20 mL) and extracted with EtOAc (50 mL×2). The combined organic layers was washed with brine (20 mL×2), dried over Na2SO4 and concentrated. The product was purified via column chromatography on silica gel eluted with 10-30% EtOAc in hexanes to afford the ether (312 mg, 78%) as a white solid. 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 0.97 (d, J=6.78 Hz, 6 H) 1.94-2.16 (m, 1 H) 2.94 (t, J=6.59 Hz, 2 H) 3.04-3.16 (m, 3 H) 3.41 (d, J=7.54 Hz, 2 H) 3.55 (t, J=6.59 Hz, 2 H) 3.87-4.01 (m, 3 H) 7.00-7.11 (m, 2 H) 7.80 (d, J=1.70 Hz, 1 H) 7.88-8.00 (m, 2H) 8.66 (d, J=1.51 Hz, 1 H); MS (ESI, pos): 432.

Provenance & Evidence