Phosphorus oxychloride → HCID 86617084, compound

Participants

Reaction Conditions

Reaction Steps

A solution of the regioisomeric mixture of 6-(2-dimethylamino-benzooxazol-5-yloxy)-1,4-dihydroxy-isoquinoline-3-carboxylic acid butyl ester and 7-(2-dimethylamino-benzooxazol-5-yloxy)-1,4-dihydroxy-isoquinoline-3-carboxylic acid butyl ester obtained as described above (1.05 g, 2.41 mmol), and phosphorus oxychloride (286 μL, 3.13 mmol) in dichloroethane (18 mL) was stirred at 120° C. in a CEM microwave apparatus for thirty minutes. The mixture was stirred with saturated sodium bicarbonate solution for twenty minutes. The organic layer was washed with brine, dried over anhydrous sodium sulfate, concentrated in vacuo. Purification by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane gave a solid (463 mg). Recrystallization from ethyl acetate (190 mL) furnished the title compound as a yellow solid (219 mg): MS: (+) m/z 456.31 (M+1).

Provenance & Evidence