Benzyl chloroformate → (+/-)-1-(5-Chloro-2-ethoxycarbonylmethoxy-phenyl)-6-fluoro-3,4-dihydro-1H-isoquinoline-2-carboxylic acid benzyl ester

Participants

Reaction Steps

To an-ice cooled solution of (±)-[4-chloro-2-(6-fluoro-1,2,3,4-tetrahydro-isoquinolin-1-yl)-phenoxy]-acetic acid ethyl ester hydrochloride (900 mg, 2.25 mmol, 1.0 eq.) and DIPEA (1.16 mL, 6.75 mmol, 3.0 eq.) in DCM (30 mL), benzyl chloroformate (0.43 mL, 2.92 mmol, 1.3 eq.) was added dropwise. Upon completion of the addition, the cooling bath was removed and the solution was stirred at r.t. for 3 hours. The reaction was quenched with 1M aq. citric acid soln. (25 mL). The layers were separated. The aq. phase was extracted with DCM (3×50 mL). The comb. org. phases were dried over MgSO4 and concentrated in vacuo. The residue was purified by flash master (column: 50 g, flow: 40 mL/min, Heptane+10% EtOAc to Heptane+50% EtOAc) to yield the title compound.

Provenance & Evidence