Electric Literature 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.
Under an atmosphere of argon, diisopropylethylamine (3.49 ml) and diphenylphosphoryl azide (2.37 ml) were added in turn to a stirred mixture of 1,5-dimethyl-1H-pyrazole-4-carboxylic acid (1.4 g), tert-butanol (4 ml) and 1,4-dioxane (40 ml) and the reaction mixture was stirred at ambient temperature for 10 minutes. The resultant mixture was heated to 110 C. for 3 hours. The solvent was evaporated and the reaction product was purified by column chromatography on silica using ethyl acetate as the eluent. There was thus obtained 4-(tert-butoxycarbonylamino)-1,5-dimethyl-1H-pyrazole (0.225 g); 1H NMR: (DMSOd6) 1.4 (s, 9H), 2.2 (s, 3H), 3.55 (s, 1H), 6.0 (br s, 1H), 9.3 (br s, 1H).
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; Jung, Frederic Henri; Morgentin, Remy Robert; Ple, Patrick; US2009/76075; (2009); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics