Acetic Acid → 4-Hydroxy-7-(pyridin-2-yloxy)-isoquinoline-3-carboxylic acid methyl ester

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Reaction Steps

A mixture of 2-{[methoxycarbonylmethyl-(toluene-4-sulfonyl)-amino]-methyl}-4-(pyridin-2-yloxy)-benzoic acid ethyl ester (745 mg), and NaOMe (0.702 mL, 0.5 M solution in HOMe) in DMF (5 mL) was stirred with ice/water bath cooling for 4 h. HOAc (2.5 eq relative to NaOMe) was added, diluted with ice/water; then the solids were collected via filtration and washed with water to give product (247 mg). Filtrate was back extracted with EtOAc; EtOAc phase was washed with water, diluted NaCl solution and dried over anhydrous sodium sulphate, filtered, concentrated and column purified to give more product (135 mg). LC MS ESI+: 297 (M+1)+.

Provenance & Evidence