Zimmermann, Diane published the artcileUnambiguous synthesis of 1-methyl-3-hydroxypyrazoles, Quality Control of 27412-71-1, the main research area is pyrazolol methyl preparation.
2,3-Dihydropyrazolo[3,2-b]oxazoles were used as intermediates in a new method for preparation of 1-methyl-3-hydroxypyrazoles. Synthesis of this bicyclic system was achieved either by alkylation of 3-hydroxypyrazole with 1,2-dibromoethane or, with better yields, by cyclization of 1-tosyl-2-(2-hydroxyethyl)pyrazol-3-ones via a nitrogen to oxygen transfer of the tosyl group. Alkylation with Me trifluoromethanesulfonate followed by dihydrooxazole ring-opening with sodium iodide led to the 1-methyl-2-(2-iodoethyl)pyrazoles. Removal of the iodoethyl chain on N-2 to give the target 3-hydroxypyrazoles was achieved either via a cyanation and then a decyanoethylation reaction or via an elimination of hydrogen iodide, followed by an iodine-based oxidation of the resulting vinylic derivative Using the latter method, 1-methyl-3-hydroxypyrazoles were obtained in 58-73% yields from the corresponding 2,3-dihydropyrazolo[3,2-b]oxazoles.
Tetrahedron published new progress about pyrazolol methyl preparation. 27412-71-1 belongs to class pyrazoles-derivatives, name is 5-Phenyl-1H-pyrazol-3(2H)-one, and the molecular formula is C9H8N2O, Quality Control of 27412-71-1.
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics