Dimethylformamide → tert-Butyl 6-cyano-5-methyl-3,4-dihydroisoquinoline-2(1H)-carboxylate

Participants

Reaction Steps

A solution of 1,1-dimethylethyl 5-methyl-6-{[(trifluoromethyl)sulfonyl]oxy}-3,4-dihydro-2(1H)-isoquinolinecarboxylate (Preparation 15; 395 mg; 1.00 mmol) in DMF (4 ml) was de-gassed under high vacuum with stirring for 15 min, followed by addition of zinc cyanide (153 mg; 1.30 mmol) and tetrakis(triphenylphosphine)palladium (0) (116 mg; 0.10 mmol) under nitrogen. The resulting deep yellow mixture was stirred at 100° C. for 6 h. The solvent was removed, the residue dissolved in ethyl acetate, and the solution washed with saturated sodium bicarbonate. The aqueous layer was further extracted with ethyl acetate, and the combined organic layers washed with brine, dried (MgSO4), and evaporated to give the crude product. Purification by flash chromatography on silica gel, eluting with a gradient of 5-25% ethyl acetate in cyclohexane, gave the title compound (214 mg) as a white solid.

Provenance & Evidence