Application of 176969-34-9, 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. 176969-34-9 name is 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, 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.
The main procedure is shown in Scheme 2. The raw products of compound 7 were synthesized via one-pot method in a flask containing compounds 5 (30 mmol), 6 (30 mmol), K2CO3 (15 mmol) and PEG1000 (0.45 mmol). The reactions were carried out under stirring at 185 C and were monitored by TLC. After reactions completion, the desired diphenylamine derivatives 7 were obtained via column chromatographic purification. Next, compounds 7 (20 mmol), reductive iron powder (60 mmol), solid NH4Cl (60 mmol) and ethanol aqueous solution (75%, 50 mL) were added. The reactions proceeded with refluxing for 3 h at 90 C and compounds 8 were obtained. Then, compound 3 (30 mmol) and SOCl2 (thionylchloride, 30 mL) were added. The mixture was heated to reflux at 90 C for 3 h. Residual SOCl2 was removed by vacuum distillation in order to obtain compound 4. Finally, the primary amines 8 (10 mmol) dissolved in dichloromethane (CH2Cl2, 5 mL) and triethylamine(Et3N, 10 mL) were added. The mixture was cooled to 0 C and compound 4 (20 mmol) dissolved in dichloromethane (CH2Cl2, 10 mL) was added dropwise under stirring at a temperature not exceeding 5 C. The final mixture was stirred at room temperature for 10 h and the target compounds 9a, 9b and 9c were purified via column chromatography and recrystallization.
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, and friends who are interested can also refer to it.