Adding a certain compound to certain chemical reactions, such as: 40711-33-9, name is Ethyl 5-oxo-2,5-dihydro-1H-pyrazole-3-carboxylate, belongs to pyrazoles-derivatives compound, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound 40711-33-9, Application In Synthesis of Ethyl 5-oxo-2,5-dihydro-1H-pyrazole-3-carboxylate
To a suspension of ethyl 5-oxo-2,5-dihydro-1 H-pyrazole-3-carboxylate (1.5 g, prepared with an analogous procedure to that described in Preparation 1 ) and Na2CO3 (1.22 g) in dry DMF (20 ml_), [(3-bromoethyl)oxy](1 ,1-dimethylethyl)dimethylsilane (1.11 ml.) was added drop wise and the mixture was stirred at 60 0C overnight. The reaction mixture was cooled down to rt and filtered to remove the Na2CO3. The filtrate was diluted with DMF and Na2CO3 (1.22g) and [(3-bromoethyl)oxy](1 ,1-dimethylethyl)dimethylsilane (2.1 ml.) were added and the mixture was stirred at 60 0C for additional 36h. After cooling, the mixture was diluted with Et2O, washed with chilly water, dried, filtered and evaporated under reduced pressure. The crude was dissolved in DCM (15 ml.) and 2,6-lutidine (1.08 ml.) and [(3-bromoethyl)oxy](1 ,1-dimethylethyl)dimethylsilane (0.86 ml.) were added at 0 0C and the mixture was stirred at rt for 1 h. The mixture was diluted in DCM, washed with NaHCO3sat and then with HCI 0.25N. The organic layer was dried and the solvent evaporated under reduced pressure. The crude was purified by flash chromatography on silica column eluting with Cy/AcOEt with a gradient of Cy from 100% to 80% to give the title compound as colourless oil (0.63 g).MS (m/z): 315 [MH]+.
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Reference:
Patent; GLAXO GROUP LIMITED; WO2009/130232; (2009); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics