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. 930-36-9, name is 1-Methylpyrazole, A new synthetic method of this compound is introduced below., category: pyrazoles-derivatives
To a stirred solution of 1 -methyl- lH-pyrazole (609 mmol) in dry ether (600 mL) under an atmosphere of nitrogen is added a solution of n-BuLi in hexane (2.6 M, 670 mmol) dropwise at -78C over a period of Ih. The reaction mixture is then stirred at this temperature for a further 1 h, and then dry carbon dioxide gas is passed through the mixture at -78C for 30 min. The reaction mixture is then allowed to warm to room temperature and quenched with water (500 mL). The aqueous phase is separated, washed with ether (500 mL) and cooled to 2-3 0C. To the stirred mixture is added concentrated aqueous hydrochloric acid until a peta of 3 is obtained. The resulting precipitate is collected by filtration, washed with ice-cold water (20 mL), dried first in open air, and then in a vacuum desiccator over P2O5 to afford 2-methyl-2H-pyrazole-3-carboxylic acid as a white powder.[0232] Compound wt: 35.3g, 45.4% yield. 1H NMR (400 MHz, DMSOi6) delta: 13.31 (IH, bs);7.50 (IH, d); 6.81 (IH, d); 4.07 (3H, s).
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; Galapagos NV; WO2009/71706; (2009); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics