1,1'-Carbonyldiimidazole → 2-[3-(3,4-Dichlorophenyl)-5-hydroxy-1-oxopentyl]-1,2,3,4-tetrahydroisoquinoline

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Reaction Steps

Beta-(3,4-Dichlorophenyl)-1,2,3,4-tetrahydro-delta-oxo-isoquinolinepentanoic acid, (14 g) in EtOAc (300 mL) was treated with carbonyldiimidazole (7.25 g) and N,N-dimethylaminopyridine (440 mg). The resulting solution was stirred at room temperature for 15 minutes and then heated at 50° C. for two hours. The reaction mixture was cooled to 0° C. and treated with a solution of NaBH4 (6.7 g) in H2O (150 mL), warmed slowly to room temperature and stirred for 12 hours. The reaction mixture was diluted with EtOAc (500 mL) and washed with 1N HCl (1×200 mL), sat. NaHCO3 (1×200 mL) and water (1×200 mL). The organic phase was dried over MgSO4, filtered and concentrated under reduced pressure to yield the crude compound as a oil. Silica gel chromatography eluting with 0-10% MeOH/CH2Cl2 gave the title compound (12.4 g). Mass spectrum (CI): 378.

Provenance & Evidence