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. Safety of Ethyl 4-pyrazolecarboxylate.
Ha, Hyeri;Shin, Changhoon;Bae, Seri;Joo, Jung Min research published 《 Divergent Palladium-Catalyzed Cross-Coupling of Nitropyrazoles with Terminal Alkynes》, the research content is summarized as follows. Facile homo-coupling of terminal alkynes, which generates conjugated diynes, is an undesired pathway in the development of transition-metal-catalyzed oxidative C-H functionalization of (hetero)arenes with terminal alkynes. By incorporating this process into a catalytic cycle, we achieved regio- and stereoselective hydroarylation of nitropyrazoles with the resulting 1,3-diynes. A simple change in the stoichiometry and oxidant allowed direct C-H alkynylation of nitropyrazoles, producing the corresponding alkynyl pyrazoles.
Safety of Ethyl 4-pyrazolecarboxylate, 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, 37622-90-5.
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics