反应详情

1,3-Dimethylisoquinoline [(Chem. Lett., 1983, p.791), 2.39 g, 15.20 mM], in conc. sulfuric acid, (15 ml), was cooled to below 4° C. A solution of potassium nitrate (1.69 g, 16.72 mM) in conc. sulfuric acid was added dropwise, maintaining the temperature below 4° C. After complete addition the solution was stirred at this temperature for a further 2 h. then warmed to room temperature for 1 h. The reaction mixture was poured into ice water and the solution basified with sodium hydroxide and extracted with DCM. The extract was washed with brine, dried and concentrated to a yellow solid. Purification by silica gel chromatography afforded the title compound as a yellow crystalline solid.

1. temperaturemaintaining the temperature below 4° C
2. additionAfter complete addition the solution
3. extractionextracted with DCM
4. washThe extract was washed with brine
5. customdried
6. concentrationconcentrated to a yellow solid
7. customPurification by silica gel chromatography