Premium
Preparation of 3(5)‐phenyl‐1‐hydroxypyrazole 2‐oxide and 4‐methyl‐3(5)‐phenyl‐1‐hydroxypyrazole 2‐oxide
Author(s) -
Hansen John F.,
Luther Matthew L.
Publication year - 1993
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570300461
Subject(s) - chemistry , oxide , medicinal chemistry , organic chemistry
Nitrosation of acrylophenone oxime or of methacrylophenone oxime with n ‐butyl nitrite in the presence of pyridine and copper(II) sulfate gives the copper complexes of the title compounds. The free 1‐hydroxypyrazole 2 ‐oxides are isolated by treating the copper complexes with dilute sodium hydroxide, filtration, and acidification of the basic filtrates. The title compounds are the first examples of 1‐hydroxypyrazole 2 ‐oxides in which the C3(5) ring position is unsubstituted.