Yield:60323-98-0 85%

Reaction Conditions:

with sulfuric acid;HNO₃ at 70; for 0.5 h;Temperature;

Steps:

1; 1-1-1-9; 2-1-2-5

Step 1: 150g of 2-bromo-5-picoline nitrogen oxides were added to 150g of concentrated sulfuric acid (mass concentration of 98%) to obtain a mixed solution, and then pumped into the preheating equipment at a flow rate of 0.5mL/min. Preheating, the preheating temperature is 70°C, and the time is 0.1h, and after the preheating is completed, it is directly pumped into the reactor. 150g of concentrated sulfuric acid (mass concentration of 98%) and 88.4g of concentrated nitric acid (mass concentration of 95%) were mixed to obtain mixed acid, then pumped into the microreactor at a flow rate of 0.4mL/min, and the temperature of the reactor was set to 70°C. Then the mixed solution and mixed acid were reacted for 0.5h, the reaction solution was added to ice water, the pH was adjusted to neutrality with ammonia water, filtered, and dried to obtain compound 158g shown in formula (II) with a purity of 98.19% (as Figure 3 and Table 1), the yield was 85%.

References:

CN114751855,2022,A Location in patent:Paragraph 0028-0033; 0038-0043; 0045-0055