In 1956,Monte, Dea Dal; Mangini, Angelo; Passerini, Riccardo published 《Heterocyclics-ultraviolet absorption spectra and chromophoric properties. III. Pyrazoles and phenylpyrazoles》.Gazzetta Chimica Italiana published the findings.Quality Control of Methyl 1H-pyrazole-3-carboxylate The information in the text is summarized as follows:
Fifty known substituted pyrazoles and phenylpyrazoles were prepared and their near ultraviolet absorption spectra were recorded in alc., alc.-water, cyclohexane, HCl, and alkali. Spectra were plotted, and absorption maximum and mol. extinction coefficients were tabulated. Substituents were Me, CO2R, Et, NH2, and NO2. Changes in spectra, mol. refraction, and basicities for pyrazole and Me derivatives confirmed a hyperconjugation effect for Me in 5- and 3-positions. Pyrazolecarboxylic acids and esters showed conjugation of CO with ring. The 208 mμ band was associated with the chromophore C:CCO2H. The 200-210 mμ band in pyrazole was assigned to the first excited level, antisymmetric combination, type B1. N-Phenylpyrazole showed conjugation between rings or between ring and imine, depending on substitution position, while 5-Me and 2-Me compounds were sterically hindered. Nitration in position 4 or 4′ caused conjugation of NO2 with imine.Methyl 1H-pyrazole-3-carboxylate(cas: 15366-34-4Quality Control of Methyl 1H-pyrazole-3-carboxylate) was used in this study.
Methyl 1H-pyrazole-3-carboxylate(cas: 15366-34-4) belongs to pyrazoles. The application of pyrazole derivatives in the development of anticancer agents has been thoroughly investigated and verified. Moreover, the medicinal features of a number of natural products incorporating pyrazole moiety such as pyrazofurin, pyrazofurin B, pyrazole-3(5)-carboxylic acid and 4-methylpyrazole-3(5)-carboxylic acid have been reported.Quality Control of Methyl 1H-pyrazole-3-carboxylate
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics