4(5)- Bromo - and - iodo-imidazoles, activated by an adjacent nitro substituent, undergo nucleophilic displacement with methoxide, phenoxide , cyclic secondary chines and cyanide. The regiochemistry of the reactions of 5-iodo-4-nitroimidazole with methoxide has been confirmed by spectroscopic and X-ray methods, and a number of erroneous structures from the literature have been revised. Some apparently anomalous reactions of methoxide with 5-halo-1,2-dimethyl-4- nitroimidazoles, and of cyanide with 4-halo-1-methyl-5-nitroimidazole have been noted. The crystal and molecular structure of 5-methoxy-1-methyl-4-nitroimidazole has been determine: by direct methods. Crystals are monoclinic, P21/c, a 10.929(3), b 8 899(2), c 7.290(2) �; β 92.87(2)�; Z 4. The structure was refined to R = 0.095 for 818 reflections (I > 2σI).
4(5)-
溴-和-
碘-
咪唑在邻近硝基取代基的活化下,与
甲醇、
苯酚、环仲胺和
氰化物发生亲核置换反应。光谱和 X 射线方法证实了 5-
碘-4-硝基
咪唑与
甲醇反应的区域
化学性质,并修正了文献中一些错误的结构。还注意到
甲醇与 5-卤代-1,2-二甲基-4-硝基
咪唑以及
氰化物与 4-卤代-
1-甲基-5-硝基咪唑的一些明显异常反应。通过直接方法确定了 5-甲氧基-
1-甲基-4-硝基咪唑的晶体和分子结构。晶体为单斜晶系,P21/c,a 10.929(3),b 8 899(2),c 7.290(2) �;β 92.87(2)�;Z 4。818 个反射(I > 2σI)的结构精制为 R = 0.095。