Dimethyl Sulfoxide → (S)-tert-Butyl 3-formyl-3,4-dihydroisoquinoline-2(1H)-carboxylate

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Reaction Conditions

Reaction Steps

To a solution of oxalyl chloride (0.798 mL, 9.15 mmol) in CH2Cl2 (11 mL) at −78° C. is added DMSO (1.08 mL, 15.25 mmol) dropwise (evolution of gas observed) and the mixture stirred at −78° C. for 1.5 h. To this is added a solution of (S)-3-hydroxymethyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester (0.803 g, 3.05 mmol) in CH2Cl2 (9 mL) and the mixture is stirred at −78° C. for 1.5 h. Triethylamine (3.4 mL, 24.41 mmol) is added and the mixture is stirred for 10 min at −78° C. and then warmed to room temperature for 1.5 h. The mixture is extracted with EtOAc (2×30 mL), washed with 1N HCl (1×35 mL) and extracted again with EtOAc (1×30 mL). The combined organic layers are washed with 1N HCl (2×30 mL) and brine (2×30 mL), dried over Na2SO4 and concentrated to afford the title compound.

Provenance & Evidence