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. 37622-90-5, name is Ethyl 4-pyrazolecarboxylate, A new synthetic method of this compound is introduced below., category: pyrazoles-derivatives
General procedure: Under the nitrogen atmosphere, a mixture of compounds 3a-d (0.24g, 1.0mmol), 1H-pyrazole-3-carboxylate (0.11g, 0.8mmol), K2CO3 (0.23g, 1.7mmol), (E)-N, N?-Dimethyl-1, 2-cyclohexanediamine (82mg, 0.96mmol), CuI (15mg, 0.08mmol) in DMF (5mL) were added in 25mL reaction vial, which was heated to 110C and stirred for 24h. Then the reaction mixture was cooled to room temperature and diluted with H2O (20mL), the resulting mixture was added EtOAc (20mL). The organic layer was separated, and the aqueous phase was extracted with EtOAc (15mL×3). The combined organic extracts were washed with brine (50mL), dried over anhydrous Na2SO4. After that, the organic phase was concentrated in a vacuum and was purified by flash column chromatography (6-12% EtOAc/petroleum ether) to afford the desired products 4a-d. Ethyl 1-(3-cyano-4-(isopropylthio)phenyl)-1H-pyrazole-4-carboxylate (4a). White solid (yield: 98.0%); 1H NMR (CDCl3) delta 8.44 (s, 1H, CH), 8.13 (s, 1H, CH), 8.05 (d, 1H, J=2.5Hz, Ar-H), 7.89 (dd, 1H, J=2.5, 8.6Hz, Ar-H), 7.64 (d, 1H, J=8.7Hz, Ar-H), 4.37 (q, 2H, J=7.1Hz, CH2CH3), 3.62 (m, 1H, CH(CH3)2), 1.44-1.40 (overlap, 3H, CH2CH3), 1.41-1.35 (d, 6H, J=1.4Hz, CH(CH3)2).
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.