10505-21-2Relevant articles and documents
Electrosynthesis of pyrazole-4-carboxylic acids by oxidation of 4-formylpyrazoles on NiO(OH)-electrode in aqueous alkaline solution
Lyalin,Petrosyan
, p. 1148 - 1153 (2013/07/26)
Electrochemical oxidation of di- and trisubstituted 4-formylpyrazoles on a Ni-anode in aqueous alkali led to the formation of the corresponding pyrazole-4-carboxylic acid in 60-90% yields. The yields of the target products depend on position of substituent in the pyrazole ring and are decreased in the following sequence of substituent at position 1 Me > Et > Ph, as well as when the aqueous medium was replaced with aqueous alcohol (50% Bu tOH). Oxidation of 4-formylpyrazoles containing Me groups at the carbon atoms of the pyrazole ring led, to monoacids and also pyrazoledicarboxylic acids in small (1.5-14%) amounts; the latter were the oxidation products of the aldehyde and the Me groups.
Reaction of Ethyl 3-Ethoxymethylene-2,4-dioxovalerate with Monosubstituted Hydrazines
Kurihara, Takushi,Uno, Toshiko,Sakamoto, Yasuhiko
, p. 231 - 233 (2007/10/02)
Reactions of ethyl 3-ethoxymethylene-2,4-dioxovalerate (1) with phenyl- and methylhydrazines are described.While the reaction of 1 with phenylhydrazine gave a mixture of ethyl 4-acetyl-1-phenylpyrazole-5-carboxylate (4) and ethyl 5-methyl-1-phenylpyrazole
