Synthetic Route of 5932-27-4, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 5932-27-4 name is Ethyl 1H-pyrazole-3-carboxylate, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
Step 1:; To a solution of 1 H-pyrazole-3-carboxylic acid ethyl ester 9a (500 mg, 3.57 mmol) in DMF (6.5 mL) is added K2C03 (542 mg, 3.93 mmol, 1 .10 equiv), Nal (1 .07 g, 7.14 mmol, 2.00 equiv) and 1 -bromo-2-fluoroethane (928 mg, 7.14 mmol, 2.00 equiv). The reaction mixture is stirred at 100 C for 48 h in a closed vial. The reaction is quenched with HCI 1 N (pH ~5-6), water is added and the mixture is extracted with EtOAc (5x). The organics are washed with brine, dried with anhydrous MgS04, filtered and concentrated. The crude mixture containing the 2 regioisomers is purified by prep HPLC. The appropriate fractions are combined, frozen and lyophilized to give 9g.UPLC-MS: 186.8 (M+H)+ 1H NMR (400 MHz, DMSO-d6) delta (ppm): 7.90 (d, 1 H, J = 2.4 Hz), 6.76 (d, 1 H, J = 2.4 Hz), 4.79 (dt, 2H, J = 47.3, 4.7 Hz), 4.53 (dt, 2H, J = 27.8, 4.7 Hz), 4.26 (q, 2H, J = 7.1 Hz), 1 .28 (t, 3H, J = 7.1 Hz).
At the same time, in my other blogs, there are other synthetic methods of this type of compound, Ethyl 1H-pyrazole-3-carboxylate, and friends who are interested can also refer to it.