<i>N</i>,<i>N</i>′,<i>N</i>,<i>N</i>′-TETRABROMO-BENZENE-1,3-DISULFONYLAMIDE AS A NOVEL REAGENT FOR OXIDATIVE AROMATIZATION OF 1,3,5-TRISUBSTITUTED PYRAZOLINES UNDER HETEROGENEOUS AND SOLVENT-FREE CONDITIONS
1,3,5-Trisubstituted pyrazolines were converted to the corresponding pyrazoles in good yields under heterogeneous and solvent-freeconditions by N,N′,N,N′-tetrabromo-benzene-1,3-disulfonylamide [TBBDA] at ambient temperature.
1,3,5-Trisubstituted pyrazolines to pyrazoles are carried out efficiently in the presence of new reagents N,N,N',N'-tetrabromo-benzene-1,3-disulfonylamine [TBBDA] and N,N'-dibromo-N,N'-1,2-ethanediylbis-(p-toluenesulphonamide) [BNBTS] in solvent-freeconditions with catalytic amounts of SiO 2 under microwave irradiation in high yields.
Trichloroisocyanuric acid as a novel oxidizing agent for the oxidation of 1,3,5-trisubstituted pyrazolines under both heterogeneous and solvent free conditions
作者:Mohammad Ali Zolfigol、Davood Azarifar、Behrooz Maleki
DOI:10.1016/j.tetlet.2004.01.038
日期:2004.3
Trichloroisocyanuric acid is used as an effective oxidizing agent for the oxidation of 1,3,5-trisubstitutedpyrazolines to their corresponding pyrazoles under both heterogeneous and also solvent free conditions with good yields at room temperature.
Microwave-assisted Aromatization of 1,3,5-Trisubstituted 2-Pyrazolines by Silica-supported N-Bromosuccinimide as a Useful Reagent under Solvent Free ‘Dry’ Condition
作者:Davood Azarifar、Behrooz Maleki
DOI:10.3987/com-04-10276
日期:——
An efficient aromatization of 1,3,5-trisubstituted2-pyrazolines to their corresponding pyrazoles by NBS was carried out under microwave irradiation and solvent-free conditions in moderate yields. It has also been observed that, by activating the NBS reagent on silica gel as a support the reaction times can be dramatically reduced and good yields are obtained.
An efficient oxidation of 2-pyrazolines and isoxazolines by bis-bromine-1,4-diazabicyclo[2.2.2]octane complex (DABCO-Br2)
作者:Davood Azarifar、Kaveh Khosravi、Rahman Ali Veisi
DOI:10.3998/ark.5550190.0011.917
日期:——
An efficient and simple procedure has been developed for the oxidation of 1,3,5-trisubstituted 4,5-dihydro-1H-pyrazoles and -isoxazoles to their corresponding aromatic derivatives promoted by bis-bromine-1,4-diazabicyclo[2.2.2]octane complex (DABCO-Br2) in acetic acid at room temperature. The products 2-pyrazoles and isoxazoles were produced in good to excellent 87-95 % and 78-95 % yields respectively