Pyrazole is an organic compound with the formula C3H3N2H. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. 37622-90-5, formula is C6H8N2O2, Name is Ethyl 4-pyrazolecarboxylate. Pyrazoles are a class of compounds that have the ring C3N2 with adjacent nitrogen atoms.Notable drugs containing a pyrazole ring are celecoxib (celebrex) and the anabolic steroid stanozolol. SDS of cas: 37622-90-5.
Lavagnino, Marissa N.;Liang, Tao;MacMillan, David W. C. research published 《 HARC as an open-shell strategy to bypass oxidative addition in Ullmann-Goldberg couplings》, the research content is summarized as follows. Herein, an alternative aryl halide activation strategy, in which the critical oxidative addition (OA) mechanism was replaced by a halogen abstraction-radical capture (HARC) sequence that allowed the generation of the Cu(III)-aryl intermediate albeit via a photoredox pathway was presented. This alternative mechanistic paradigm decoupled the bond-breaking and bond-forming steps of the catalytic cycle to enable the use of many previously inert aryl bromides. Overall, this mechanism allowed access to both traditional C-N adducts at room temperature as well as a large range of previously inaccessible Ullmann-Goldberg coupling products including sterically demanding ortho-substituted heteroarenes, e.g., I.
37622-90-5, Ethyl 4-pyrazolecarboxylate, also known as Ethyl pyrazole-4-carboxylate, is a useful research compound. Its molecular formula is C6H8N2O2 and its molecular weight is 140.14 g/mol. The purity is usually 95%.
Ethyl pyrazole-4-carboxylate is a low yield, transition metal salt that is used in the synthesis of pyrazoles. It can be synthesized by the reaction of sodium ethoxide with ethyl chloroformate and a Grignard reagent. Sodium ethoxide is added to a suspension of sodium chloride and dried ethyl chloroformate, followed by addition of magnesium turnings. The mixture is refluxed for one hour, cooled, and filtered to give crystals. Ethyl pyrazole-4-carboxylate is used in the preparation of ethyl esters from aliphatic alcohols by reacting with boron trichloride or phosphorus pentachloride. It participates in certain chemical reactions as a byproduct and can damage equipment during chemical reactions. The yield of this compound can be increased by using an excess amount of Grignard reagent or adding hexamethylenetetramine to the reaction mixture, SDS of cas: 37622-90-5
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics