title: Regioselective synthesis of polysubstituted pyrazoles and isoxazoles.
abstract: A regioselective synthesis has been developed for the preparation of unsymmetrical 1,3,5-triaryl-4-alkylpyrazolines and -pyrazoles by treatment of alpha-benzotriazolyl-alpha,beta-unsaturated ketones with monosubstituted hydrazines followed by alkylation at the 4-position of the pyrazoline ring. Reaction of alpha-benzotriazolyl-alpha,beta-unsaturated ketones with hydroxylamine gives 3,5-disubstituted isoxazoles regioselectively.
authors.affiliation: Department of Chemistry, University of Canterbury, Christchurch, New Zealand. katritzky@chem.ufl.edu
authors.forename: A R
authors.initials: AR
authors.lastname: Katritzky
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: M V
authors.initials: MV
authors.lastname: Voronkov
authors.forename: P J
authors.initials: PJ
authors.lastname: Steel
mesh_terms: D018360:Crystallography, X-Ray; D007555:Isoxazoles / Q000138:chemical synthesis*; D011720:Pyrazoles / Q000138:chemical synthesis*
chemical_list: D007555:Isoxazoles; D011720:Pyrazoles