Electric Literature of 37622-90-5, A common heterocyclic compound, 37622-90-5, name is Ethyl 4-pyrazolecarboxylate, 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.
4-Ethylpyrazole carboxylate (10g, 71.40 mmol) is placed in an oven -dried flask under an atmosphere of argon. Dry THF (100 mL) is added followed by the dropwise addition of lithium aluminium hydride (1 M in THF, 100 mL, 100 mmol). Once the addition is complete the reaction mixture is stirred at 50C. The reaction is shown to be complete by NMR after 4 hours. The reaction mixture is cooled on an ice-bath and the reaction mixture is quenched with water (3.8 mL) then 15% sodium hydroxide (3.8 mL) and finally water again (11.4 mL). The solvent is removed in vacuo and the solid is placed in a Soxhlet apparatus. THF is refluxed through the system for 24 hours. The solvent is removed in vacuo to give the title compound.1H NMR (MeOD, 400 MHz); 7.60 (s, 2H), 4.55 (s, 2H).
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; NOVARTIS AG; NOVARTIS PHARMA GMBH; WO2008/6563; (2008); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics