Belmar, J. published the artcileSynthesis and tautomerism of new 1-n-alkyl-5-pyrazolone derivatives, Related Products of pyrazoles-derivatives, the main research area is pyrazolone alkylation acylation nitrosation tautomerism.
3-Phenyl-5-pyrazolone (1) is selectively alkylene at position 1 in 40% yield. The alkylated compound (2) is acylated (3) in 60% yield and nitrosated (4) in 80% yield. According to the spectroscopic data a N-H or O-H structure can be proposed for 1 in DMSO. The proton may be at N-2 or on the oxygen at C-5, resp. The alkylated compound 2 exists as 5-pyrazolone in chloroform with a CH2 at C-4. In DMSO, 2 is a 5-hydroxypyrazole. For compound 3 in chloroform the structure corresponds to 4-acyl-5-hydroxypyrazole. For compound 4 in chlorolform there is one tautomer with a 4-nitroso-5-hydroxypyrazole structure while in DMSO the same 4-nitroso-5-hydroxypyrazole (92%) and a 4-nitroso-5-pyrazolone (8%) tautomer can be found.
Boletin de la Sociedad Chilena de Quimica published new progress about Acylation (of 1-alkyl-3-phenyl-5-pyrazolone). 27412-71-1 belongs to class pyrazoles-derivatives, name is 5-Phenyl-1H-pyrazol-3(2H)-one, and the molecular formula is C9H8N2O, Related Products of pyrazoles-derivatives.
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics