Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 5334-40-7, name is 4-Nitro-1H-pyrazole-3-carboxylic acid, A new synthetic method of this compound is introduced below., HPLC of Formula: C4H3N3O4
Preparation of the Resin (ii):30 g of Rink resin (PolymerLab; 0.99 mmol/g) is swollen in 150 ml of DMF. After stirring for 10 minutes, the DMF is filtered off and replaced with 150 ml of a solution of piperidine in DMF (50/50, v/v). The mixture is stirred for 1 hour and then filtered. The resin is washed successively with five times 150 ml of DMF, twice 150 ml of methanol and three times 150 ml of DMF. Next, a solution of 14.1 g of 4-nitro-3-pyrazolecarboxylic acid (90 mmol, 3 eq.) and 13.8 g of HOBt (90 mmol, 3 eq.) in 150 ml of DMF is added to the resin, immediately followed by 13.8 ml of DIC (90 mmol; 3 eq.). The mixture is stirred for 16 hours at room temperature. The solution is filtered and the resin is washed successively with five times 150 ml of DMF, twice 150 ml of methanol, three times 150 ml of DMF and then with 150 ml of a 1 M SnCl2 solution (33 g in 150 ml). The mixture is stirred at room temperature for 24 hours and is then filtered, and the resin is washed with five times 150 ml of DMF, twice 150 ml of methanol, three times 150 ml of DCM and twice 150 ml of ethyl ether. After drying under vacuum, 31 g of intermediate resin (ii) are isolated.
The synthetic route of 5334-40-7 has been constantly updated, and we look forward to future research findings.