Cycloaddition reactions of 1.3-benzothiazines v synthesis of new tetracyclic ring systems
作者:Lajos Fodor、János Szabó、Gábor Bernáth、Pál Sohár
DOI:10.1016/s0040-4039(01)90100-5
日期:1984.1
New tetracyclic derivatives (3a,b, 5, 8) similar to protoberberines, but containing a lactam structural element and other hetero atoms besides the bridge-head nitrogen in rings B and C, were prepared by cycloaddition of 6,7-dimethoxy-2H-1,3-benzothiazine (1a) with o-substituted aromatic carboxylic acid derivatives (2a,b, 4) and from 4- methyl-6,7-dimethoxy-2H-1,3-benzothiazine (1b) with 3.5-dinitrobenzoyl
通过环加成6,7-二甲氧基-2H,制备了类似于原小ber碱的新四环衍生物(3a,b,5、8),除了环B和C中的桥头氮外,还包含内酰胺结构元素和其他杂原子。 -1,3-苯并噻嗪(1a)与邻位取代的芳族羧酸衍生物(2a,b,4)和4-甲基-6,7-二甲氧基-2H-1,3-苯并噻嗪(1b)与3.5-二硝基苯甲酰基氯化物。