反应详情

温度

5 °C

Cold hypophosphorous acid (50%, 20 ml) was added slowly to a solution of sodium nitrite (3.7 g) in sulphuric acid (100 ml) diluted with water (50 ml), maintaining the temperature from -5° to -10°. The reaction mixture was cooled to -15°, and a cooled solution containing 5-amino-6-chloro-4-oxo-10-propyl-4H-pyrano[3,2-g]quinoline-2,8-dicarboxylic acid (0.753 g) in acetic acid (200 ml), added over two hours maintaining the temperature between -10° and -15°. When the addition was complete, the slurry was stirred for an hour, and the mixture allowed to warm to 5° C. The mixture was stored in a refrigerator overnight, with the evolution of nitrogen and oxides of nitrogen. Filtration of the reaction mixture, and recrystallisation from ethyl acetate, gave 0.43 g of the title compound, mp 338°-340° C.

1. temperaturemaintaining the temperature from -5° to -10°
2. temperatureThe reaction mixture was cooled to -15°
3. additionadded over two hours
4. temperaturemaintaining the temperature between -10° and -15°
5. additionWhen the addition
6. filtrationFiltration of the reaction mixture, and recrystallisation from ethyl acetate