Sodium Methoxide → 4-Hydroxy-8-phenoxy-isoquinoline-3-carboxylic acid methyl ester

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Reaction Conditions

Reaction Steps

To a stirred solution of 2-{[methoxycarbonylmethyl-(toluene-4-sulfonyl)-amino]-methyl}-3-phenoxy-benzoic acid ethyl ester (5.07 g, 0.01 mol) in anhydrous methanol (22 mL) was added dropwise a mixture of sodium methoxide solution (30% wt, 5.6 mL) and anhydrous methanol (4 mL) at 0° C. The mixture was stirred at 0° C. for 10 minutes and then at room temperature for additional 3 h before it was concentrated in vacuo. Water was added and the pH of the slurry was adjusted with aqueous 1 N HCl to pH=10. The precipitate formed was separated by filtration, washed with water, saturated sodium bicarbonate solution, and water before it was dried in vacuo to give the title compound as a white solid (2.21 g): 1H NMR (CDCl3, 200 MHz): δ=11.73 (s, 1H), 9.21 (s, 1H), 8.06 (d, J=8.2 Hz, 1H), 7.61 (t, J=8.0 Hz, 1H), 7.40 (m, 2H), 7.13 (m, 4H), 4.10 (s, 3H).

Provenance & Evidence