Hexamethylphosphoramide → 4-Amino-3-(4-methylisoxazole-5-ylcarbonylamino)quinoline

Beteiligte Stoffe

Reaktionsschritte

To a solution of 300 mg of 4-methyloxazole-5-carboxylic acid in 4 ml of hexamethylphosphoramide and 0.4 ml of acetonitrile is added 268 mg of thionyl chloride at -5°-0° C. under nitrogen. After stirring at the same temperature for 30 minutes, 340 mg of 3,4-diaminoquinoline A1 is added and stirred at 0°-5° C. for 3 hours. The mixture is diluted with ice-water and neutralized with saturated aqueous sodium bicarbonate. The resulting solid is filtered and washed with water to give 425 mg of 4-amino-3-(4-methylisoxazole-5-ylcarbonylamino)quinoline as crude crystals. It is suspended in 12 ml of Dowtherm A (Dow Chemimical Co.) and refluxed for 2.5 hours. The cooled mixture is diluted with 50 ml of n-hexane and the resulting solid is collected by filtration. It is chromatographed on silica gel with dichloromethane-methanol (20:1 v/v) as eluent to yield a crude solid which is recrystallized from ethyl acetate-methanol, giving 297 mg of C99 as pale yellow crystals.

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