Preparation of benzofuroxans and benzofurazans of 2,3,4,5-tetrahydrobenzo[b] [1,4]dioxocin and related compounds
作者:Ioannis M. Takakis、Phaedon M. Hadjimihalakis
DOI:10.1002/jhet.5570270212
日期:1990.2
novel benzofuroxans 1d, 2 and benzofurazans 3,4 have been prepared in good yields. Nitration of 5c furnished the mononitro-derivatives 6a and 6b in the unusually high relative ratio 6a:6b of 23:77. Direct nitration of 5c or 6a + 6b afforded the unexpected dinitro-derivative 8b as the major product along with the isomeric 8a, 8c and 8d. Improvement in the yield of 5c (to 86%) is reported.
新型苯并呋喃类化合物1d,2和苯并呋喃类化合物3,4的制备得率很高。5c的硝化提供了单硝基衍生物6a和6b,其异常高的相对比例6a:6b为23:77。5c或6a + 6b的直接硝化反应提供了出乎意料的二硝基衍生物8b和主要异构体8a,8c和8d ,它们是主要产物。据报道5c的产率提高(至86%)。