Reference of 31728-75-3, A common heterocyclic compound, 31728-75-3, name is 1,5-Dimethyl-1H-pyrazole-4-carboxylic acid, molecular formula is C6H8N2O2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
The 1.60g of 1,5-dimethyl -1H- pyrazole-4-carboxylic acid, 1.23 g of oxalyl chloride, approximately 15mg of N, N- dimethylformamide and 50mL of tetrahydrofuran was stirred at 25 1 hour. The reaction mixture was concentrated under reduced pressure to give 1,5-dimethyl -1H- pyrazole-4-carbonyl chloride.The 2.34 g of aluminum chloride in a mixture of 3.42g of sodium azide, and 50mL of tetrahydrofuran was stirred with heating under reflux for 2 hours. After ice-cooling the reaction mixture, the 1,5-dimethyl -1H- pyrazole-4-carboxamido mixture was added to the reaction mixture, followed by heating and stirring at reflux for 3 days. After cooling, the reaction mixture was added to 5.27g of sodium nitrite and a mixture of 100mL of water while stirring. The mixture was acidified with concentrated hydrochloric acid and then extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate, and then concentrated under reduced pressure to give 1.6g of 1- (1,5-dimethyl -1H- pyrazol-4-yl) -1,4-dihydro-tetrazole – 5-one.
The synthetic route of 31728-75-3 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Sumitomo Chemical Co., Ltd.; Dong, Xiuping; Gao, Qiaohuangshu; (181 pag.)CN105636955; (2016); A;,
Pyrazole – Wikipedia,
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