diethylene glycol affords the corresponding pyridazines in high yields with evolution of hydrogen sulfide. The above procedure is generally applicable to the preparation of a wide variety of 3,6-disubstituted pyridazines which are of structural interest and otherwise difficult to prepare.
一系列 3-thiapentane-1,5-diones 与
肼在催化量的
对甲苯磺酸存在下在回流
乙醇中缩合,以极好的收率得到 2,7-dihydro-1,4,5-thiadiazepines。后一种化合物在回流的
二甘醇中热分解以高产率提供相应的
哒嗪,并放出
硫化氢。上述程序通常适用于制备各种具有结构意义且难以制备的 3,6-二取代
哒嗪。