4-benzothiazines 4 and 12, respectively, by using the dioxane/p-toluenesulfonic acid or polyphosphoric acid/chloroform systems. In contrast, in the same reaction conditions, 1,4-benzothiazines 5a-h do not provide the expected pyrrolobenzothiazines 7, and as for 5c-h considerable amount of the 2-amino-phenyl-sulfide 8 was obtained. The results of microbiological assays are reported.
                                    N-(2,2-二烷氧基乙基)-1,4-苯并
噻嗪内酰胺2和1,4-苯并
噻嗪-砜10的环化反应生成相应的
吡咯并[1,2,3- de ] -1,4-苯并
噻嗪4分别通过使用
二恶烷/
对甲苯磺酸或多
磷酸/
氯仿体系来制备图12和12所示的化合物。相反,在相同的反应条件下,1,4-苯并
噻嗪5a-h不能提供预期的
吡咯并苯并
噻嗪7,至于5c-h,获得了大量的2-
氨基-苯基-
硫化物8。报告了微
生物测定的结果。