Chlorodimethylsulfonium Chloride–Mediated Formation of Phenyl-α-chloroazoalkanes
摘要:
Phenylhydrazones (1) are efficiently converted into phenyl--chloroazoalkanes (2) upon treatment with chlorodimethylsulfonium chloride. Pendent olefins, silyl ethers, and the phenyl ring of the hydrazone are stable to these reaction conditions.
Efficient solvent-free synthesis of thiazolidin-4-ones from phenylhydrazine and 2,4-dinitrophenylhydrazine
作者:Patrícia D. Neuenfeldt、Bruna B. Drawanz、Geonir M. Siqueira、Claudia R.B. Gomes、Solange M.S.V. Wardell、Alex F.C. Flores、Wilson Cunico
DOI:10.1016/j.tetlet.2010.04.026
日期:2010.6
An efficient solvent-free synthesis of thiazolidinones from reaction of mercaptoacetic acid, aldehydes (benzaldehyde and valeraldehyde) or ketones (cyclopentanone and cyclohexanone), and hydrazines (phenylhydrazine and 2,4-dinitrophenylhydrazine) is reported. The compounds were generally characterized by spectroscopic techniques and specifically for 2-cyclohexanyl-3-(N-phenyl)-1,3-thiazolidin-4-one
Several aldehyde and ketonephenylhydrazones were electrooxidized in MeOH. Electrooxidation in the presence of KI or tetraethylammonium p-toluenesulfonate as the supporting electrolyte afforded the corresponding methoxy(phenylazo)alkanes. whereas electrooxidation in the presence of KI, NaCN, and HOAc afforded the cyano(phenylazo)alkanes.
几种醛和酮苯腙在 MeOH 中被电氧化。在 KI 或对甲苯磺酸四乙基铵作为支持电解质的情况下进行电氧化,得到相应的甲氧基(苯偶氮)烷烃。而在 KI、NaCN 和 HOAc 存在下的电氧化得到氰基(苯偶氮)烷烃。
Rearrangement of 3,3-Disubstituted 1-Aryl-4,5-dihydro-5-oxo-3<i>H</i>-1,2,4-triazolium Tetrafluoroborates; Part 2. A Convenient Synthesis of 1,5-Annulated 1,2-Dihydro-2-phenyl-3<i>H</i>-1,2,4-triazol-3-ones
作者:Hubert Gstach、Patrick Seil
DOI:10.1055/s-1990-27022
日期:——
1-Isocyanato-1-(phenylazo)cycloalkanes 3 react with tetrafluoroboric acid to yield 3-spiro substituted 4,5-dihydro-5-oxo-1-phenyl-3H-1,2,4-triazolium tetrafluoroborates 4. Compounds 4 rearrange with ring expansion in good yield to give, after basic workup, 1,5-annulated 1,2-dihydro-2-phenyl-3H-1,2, 4-triazol-3-ones 5.
Certain indole derivatives, and especially certain 1,2,3,4-tetrahydrocarbazoles, 1,2,3,4-tetrahydro-.gamma.-carbolines and 1,2,3,4-tetrahydropyrrolo-[3,4-b]indoles are prepared by reacting the appropriate phenylhydrazine salt and ketone in the presence of a weakly basic solvent such as pyridine, quinoline, N,N-dimethylaniline, picoline or lutidine at a temperature in the range of about 50.degree. to 180.degree. C.
Regioselective Synthesis of 5-Trifluoromethyl Pyrazoles by the [1+4] Cyclization of Phenylhydrazones with N-Aryl Trifluoroacetimidoyl Iodides
作者:Hong-Bin Yu、Wei-Yuan Huang
DOI:10.1055/s-1997-3274
日期:1997.6
Treatment of the phenylhydrazone of a methyl ketone (2) or cyclohexanone (3) with N-aryl trifluoroacetimidoyl iodide (1) in the presence of excess sodium hydride resulted in a [1+4] cyclization to give 5-trifluoromethyl pyrazoles (4, 5) regioselectively. The structure of products 4 or 5 was confirmed by the 13C NMR spectra.