Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns. 37622-90-5, formula is C6H8N2O2, Name is Ethyl 4-pyrazolecarboxylate. 1-Methyl-5-(trifluoromethyl)pyrazole underwent deprotonation and subsequent carboxylation mainly or exclusively at either the 4-position of the heterocycle or at the nitrogen-attached methyl group. Application of C6H8N2O2.
Kim, Kundo;Lee, Yunmi research published 《 Copper-Catalyzed Hydroamination of Oxa- and Azabenzonorbornadienes with Pyrazoles》, the research content is summarized as follows. An efficient and highly chemo- and stereoselective copper-catalyzed hydroamination of oxa- and azabenzonorbornadienes with various pyrazole derivatives is described. This catalytic process is promoted by the presence of N-heterocyclic carbene ligands and KOt-Bu under mild and simple reaction conditions, and allows for the direct synthesis of new and versatile functionalized oxa(aza)benzonorbornyl pyrazoles I (R = H, 6,7-(OMe)2, 6,7-(Br)2, etc; X = O, N(Boc), N(Ac), etc.; R1 = H, 4-Me, 4-Cl, etc.) starting from readily available oxa(aza)bicyclic alkenes. The synthetic utility of this method was demonstrated by the transformation of the obtained products into pyrazolyl-substituted naphthalenes.
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, Application of C6H8N2O2
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics