9,10-Dimethylphenanthrene and 9-methyl-10-ethylphenanthrene gave 9-methyl-10-nitromethylphenanthrene and 9-ethyl-10-nitromethylphenanthrene, respectively, as major product, when treated with fuming nitric acid in dichloromethane at low temperatures. In contrast, 9,10-diethylphenanthrene yielded a comparable mixture of products arising from side-chain nitration and side-chain nitrooxylation, which on chromatography over deactivated alumina gave 9-ethyl-10-(α-nitroethyl)phenanthrene and 9-ethyl-10-(α-hydroxyethyl)phenanthrene as main isolable products. 9-Methylphenanthrene and 9-ethylphenanthrene were both simply nitrated at the ring position to give the corresponding 9-alkyl-10-nitrophenanthrenes in good yields. No side-chain attack was observed. Factors responsible for determining which one of the competitive pathways will be followed have been discussed.
9,10-二甲基菲和9-甲基-10-乙基
菲在低温下与溶于
二氯甲烷的浓
硝酸反应时,主要产物分别为9-甲基-10-硝基甲基
菲和9-乙基-10-硝基甲基
菲。相比之下,
9,10-二乙基菲产生了由侧链硝化和侧链硝氧化反应生成的类似产物混合物,在用脱活铝土矿进行色谱分离时,得到的主要可分离产物为9-乙基-10-(α-硝基乙基)
菲和9-乙基-10-(α-羟基乙基)
菲。
9-甲基菲和
9-乙基菲也仅在环的位置进行硝化,得到相应的9-烷基-10-硝基
菲,产率良好。未观察到侧链攻击。文中讨论了影响选择竞争反应路径的因素。