8-Isoquinolinol

To a stirred solution of 8-methoxyisoquinoline (7. 0g, 44mmol) in anhydrous CH2C12 (60 mL) cooled in an ice bath, was added over 0. 5H, boron tribromide, 1M in CH2C12 (Aldrich 21, 122-2) (219 mL, 219 mmol). The reaction mixture was warmed to room temperature, heated at reflux for 2H, cooled TO-78°C, and decomposed by the addition OF CH30H (150 ML). The reaction mixture was warmed to room temperature, heated at reflux for 0. 5h and the solvent removed in vacuo. The residue was azeotrope with CH30H (3 x 100 ML) and suspended in H20 (150 mL). To this suspension was added CH2C12 (300 mL) and with vigorous stirring NEUTRALISED to c. a. 7.0 with ammonia (0. 88). The CH2C12 layer was separated and the aqueous layer extracted with CH2C12 (2 x 200 ML). The combined layers were dried (NA2S04) and the solvent removed in vacuo. The residue was purified by flash column chromatography to give the title compounds a pale yellow solid. (6.87g, 98percent). 1H NMR (400MHZ, DMSO-d6) 6 7.10 (1H), 7.45 (1H), 7. 65. (1H, ), 7.75 (1H), 8.50 (1H), 9.50 (1H), 10.90 (1H).n 49. lmL dimethyl sulfoxide and 12.3 mL Water was added 10 g of a mixture of 61.35 mmol 8-chloroisoquinoline, 0.8], 3.07 mmol of copper acetylacetonate, 2.71 g, 64.42 mmol-hydrated hydroxide and 0.92 g, 3.07 mmol L-1, 3-bis (4-hydroxy-2, 6-dimethylphenyl) urea. The reaction solution was stirred at 130 ° C for 24 hours under nitrogen. After the reaction solution to be stirred was cooled, The solution was acidified with 2 mol / L HC1 to ρH- = 5, The mixture was extracted with ethyl acetate, The extracted organic phase was washed with saturated brine, Dried over anhydrous sodium sulfate and dried, The crude product was separated by column chromatography to give 8-hydroxyisoquinoline 6.41 g, the total yield was 72percent.To a stirred solution of 8-methoxyisoquinoline (7. 0g, 44mmol) in anhydrous CH2C12 (60 mL) cooled in an ice bath, was added over 0. 5H, boron tribromide, 1M in CH2C12 (Aldrich 21, 122-2) (219 mL, 219 mmol). The reaction mixture was warmed to room temperature, heated at reflux for 2H, cooled TO-78C, and decomposed by the addition OF CH30H (150 ML). The reaction mixture was warmed to room temperature, heated at reflux for 0. 5h and the solvent removed in vacuo. The residue was azeotrope with CH30H (3 x 100 ML) and suspended in H20 (150 mL). To this suspension was added CH2C12 (300 mL) and with vigorous stirring NEUTRALISED to c. a. 7.0 with ammonia (0. 88). The CH2C12 layer was separated and the aqueous layer extracted with CH2C12 (2 x 200 ML). The combined layers were dried (NA2S04) and the solvent removed in vacuo. The residue was purified by flash column chromatography to give the title compounds a pale yellow solid. (6.87g, 98%). 1H NMR (400MHZ, DMSO-d6) 6 7.10 (1H), 7.45 (1H), 7. 65. (1H, ), 7.75 (1H), 8.50 (1H), 9.50 (1H), 10.90 (1H). (3.0 g, 20.69 mmol), PtO2 (0.1 g) was dispersed in glacial acetic acid (100 mL).After the nitrogen was replaced, hydrogen was introduced, and then stirred at 65 C for 2 days.Filtration through celite, and the filtrate was evaporated to dryness under reduced pressure.The residue obtained pure compound 52A (3.12g, 72% yield) crystallized from methanol and diethyl ether, Yellow solid.