3-Alkylthio and 3-aminopyrazolo[3,4-<i>D</i>]pyridazines. Ring contraction of pyridazino[4,5-<i>e</i>][1,3,4]thiadiazines<i>via</i>extrusion of sulfur
作者:Kenji Kaji、Hiromu Nagashima、Yasushi Ohhata、Keizo Tabashi、Hirohisa Oda
DOI:10.1002/jhet.5570220140
日期:1985.1
2-alkylthio-4H-pyridazino[4,5-e][1,3,4]thiadiazine derivatives 2. Oxidative cyclization of 5-(4-substituted 1-methylthiosemicarbazido)-3(2H)-pyridazinone derivatives 4 with N-bromosuccinimide also gave 2-substituted amino-4H-pyridazino[4,5-e][1,3,4]thiadiazine derivatives 5. Heating of 2 and 5 resulted in ring contraction to afford the corresponding pyrazolo[3,4-d]pyridazine derivatives 6, 7 via sulfur extrusion
4-氯-2-甲基-5-(1-甲基肼基)-3(2 H)-哒嗪酮(1)与二硫化碳反应,然后烷基化,生成2-烷硫基-4 H-吡啶并[4,5- e ] [1,3,4]噻二嗪衍生物2。5-(4-取代的1-甲基硫代半碳杂多)-3(2 H)-哒嗪酮衍生物4与N-溴代琥珀酰亚胺的氧化环化反应也产生了2-取代的氨基-4 H-吡啶并[4,5- e ] [1,3, 4]噻二嗪衍生物5。加热2和5导致环收缩,得到相应的吡唑并[3,4- d硫哒嗪衍生物6、7 通过硫磺挤出。与一种哒嗪并[4,5- e ] [1,3,4]噻二嗪(2,5)和另一种哒嗪[ 9,11,13, 15)。