Water → 2-tert-butyl 3-methyl (3S)-7-hydroxy-1,2,3,4-tetrahydroisoquinoline-2,3-dicarboxylate

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Reaction Steps

To a solution of (3S)-7-hydroxy-3,4-dihydro-1H-isoquinoline-2,3-dicarboxylic acid 2-tert-butyl ester (1.47 g, 5.0 mmol) in dry DMF (25 mL) at ambient temperature, was added iodomethane (1.2 eq., 6.0 mmol, 0.37 mL) and diisopropylethylamine (1.5 eq. 7.5 mmol, 1.31 mL) in succession, and the reaction mixture was stirred at rt for 3-4 hours, at which point LC/MS analysis showed the presence of product. The reaction mixture was poured into 50 mL of water and extracted with DCM (3×50 mL) and the combined DCM extracts were washed with water (3×50 mL) and brine (50 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by flash column chromatography on silica (ethyl acetate/hexanes) to afford (3S)-7-hydroxy-3,4-dihydro-1H-isoquinoline-2,3-dicarboxylic acid 2-tert-butyl ester 3-methyl ester (1.13 g).

Provenance & Evidence