反应详情

A mixture of 5-amino-1-ethyl-4-oxo-1,4-dihydro-[1,3]dioxolo[4,5-g]cinnoline-3-carboxylic acid (3.6 g, 12.99 mmol) in hydrochloric acid (conc) (20 ml) was stirred at room temperature and sodium nitrite (0.986 g, 14.28 mmol) in water (7 mL) was added dropwise to maintain the temperature bellow 45° C. Stirring continued for 5 h. The solution was poured into 50 ml of water and was allowed to stand overnight in the refrigerator. Precipitate was collected by filtration and dried over drierite in a desiccator to yield 3-Carboxy-1-ethyl-4-oxo-1,4-dihydro-[1,3]dioxolo[4,5-g]cinnoline-5-diazonium chloride (3.15 g, 9.67 mmol, 74.5% yield). LCMS: (M+H)+: 326.2

1. temperatureto maintain the temperature bellow 45° C
2. stirringStirring
3. waitto stand overnight in the refrigerator
4. filtrationPrecipitate was collected by filtration
5. dry with materialdried over drierite in a desiccator