Aromatic Nitration under Neutral Conditions Using Nitrogen Dioxide and Ozone as the Nitrating Agent. Application to Aromatic Acetals and Acylal
作者:Hitomi Suzuki、Shuji Yonezawa、Tadashi Mori
DOI:10.1246/bcsj.68.1535
日期:1995.6
can be nitrated smoothly with nitrogen dioxide in ice-cooled dichloromethane or acetonitrile in the presence of ozone and magnesium oxide to give ortho- and para-nitro derivatives as the major product in good combined yields, the acetal ring as a protective group remaining almost intact. An acylal derived from benzaldehyde similarly undergoes nitration on the aromatic ring to give an isomeric mixture
在臭氧和氧化镁存在下,芳香羰基化合物衍生的环状缩醛可以在冰冷的二氯甲烷或乙腈中用二氧化氮顺利硝化,得到邻和对硝基衍生物作为主要产物,收率良好,缩醛环作为保护基团几乎完好无损。衍生自苯甲醛的酰基类似地在芳环上硝化,得到三种硝基化合物的异构混合物,其中邻位异构体和间位异构体占主导地位,而芳族原酸酯迅速分解为简单的母体酯。中性条件下的环硝化反应被解释为一种非经典机制,其中三氧化氮作为初始亲电子试剂参与。