Maquestiau, A. published the artcileTautomerism in the pyrazolinone series. II. Solvent influence on the prototropic equilibrium of N1 substituted pyrazolin-5-ones, Related Products of pyrazoles-derivatives, the publication is Bulletin des Societes Chimiques Belges (1973), 82(3-4), 215-31, database is CAplus.
The solvent effect on the tautomerism of N-1 substituted pyrazolin-5-ones was determined by ir. The % keto form (I) was larger than the % enol form in nonpolar solvents; the % keto form decreased in aprotic solvents with their increasing basicity. In aprotic solvents, the concentration of the NH form (II) was related to the solvent acidity.
Bulletin des Societes Chimiques Belges published new progress about 14580-22-4. 14580-22-4 belongs to pyrazoles-derivatives, auxiliary class Organic Pigment, name is 1-(2-Chlorophenyl)-3-methyl-5-pyrazolone, and the molecular formula is C10H9ClN2O, Related Products of pyrazoles-derivatives.
Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics