Catalytic Activity of 1,3-Dibromo-5,5-dimethylhydantoin (DBH) in the One-Pot Transformation of<i>N</i>-Arylglycines to<i>N</i>-Arylsydnones in the Presence of NaNO<sub>2</sub>/Ac<sub>2</sub>O under Neutral Conditions: Subsequent Bromination of these Sydnones to their 4-Bromo Derivatives
作者:Davood Azarifar、Hassan Ghasemnejad-Bosra
DOI:10.1055/s-2006-926380
日期:——
1,3-Dibromo-5,5-dimethylhydantoin (DBH) has been found to efficiently catalyze the one-pot conversion of various N-arylglycines through N-nitrosation and cyclization to sydnones in combination with NaNO2 and Ac2O in high yields (80-94%) under mild and neutral conditions. Also, it was shown that DBH can conveniently promote the bromination of these sydnones to their 4-bromo substituted congeners in excellent yields in DMF at room temperature.
研究发现,在温和的中性条件下,1,3-二溴-5,5-二甲基海因(DBH)可与 NaNO2 和 Ac2O 结合,高效催化各种 N-芳基甘氨酸通过 N-亚硝基化和环化反应一锅转化为茚酮类化合物,收率高达 80-94%。此外,研究还表明,DBH 可以方便地促进这些茚酮在室温下于 DMF 中溴化成其 4-溴取代的同系物,收率极高。