Hydrochloric Acid → Methyl 4-hydroxy-7-phenoxyisoquinoline-3-carboxylate

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Reaction Steps

To a mixture of 2-{[Methoxycarbonylmethyl-(toluene-4-sulfonyl)-amino]-methyl}-4-phenoxy-benzoic acid methyl ester (14.0 g, 28.1 mmol) in DMSO (56 mL) was slowly added 30% NaOMe in MeOH (15.3 mL, 84.3 mmol). The resultant mixture was stirred at room temperature for 30 min and poured into 200 mL of ice and water. It was slowly acidified by conc. HCl aq. solution (10 mL) and then extracted with EtOAc. Organic layer was washed with 3% NaHCO3 solution, water and brine, and was dried over Na2SO4, filtered and concentrated. Crude produce was purified by silica gel chromatography to provide the title compound 6.05 g (20.5 mmol) in 72.9% yield. 1H NMR in CDCl3, δ in ppm: 11.7 (s, 1H), 8.59 (s, 1H), 8.36 (d, 1H, J=9.2 Hz), 7.55-7.1 (m, 7H), 4.07 (s, 3H).

Provenance & Evidence