The synthesis of pyrroloisoquinolinediones from phthalic anhydride and pyrrolylmagnesium halides has been improved. A new synthesis, by cyclization of the novel 1-(2-carboxybenzoyl)pyrroles, was generally preferable. From pyrrolylmagnesium bromide and dimethylmaleic anhydride, followed by cyclization, 6,7-dimethylindolizine-5,8-dione was obtained. The process failed with maleic anhydride. Pyrrolo[1,2-b]isoquinoline-5,10-dione could be dinitrated in the pyrrolo ring (with some oxidation to isoquinoline-1,3,4-trione), reduced to 10-hydroxy-3,5-dihydropyrrolo[1,2-b]isoquinolin-5-one by zinc and acetic acid, and hydrogenated over palladium on carbon to 10-hydroxy-1,2,3,5-tetrahydropyrrolo[l,2-b]isoquinolin-5-one. The dihydro derivative reverted in air to the dione.

中文翻译：

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吡咯并[1,2 - b ]异喹啉-5,10-二酮和吲哚嗪-5,8-二酮

由邻苯二甲酸酐和吡咯基卤化镁合成吡咯并异喹啉二酮已得到改进。通常优选通过新的1-（2-羧基苯甲酰基）吡咯的环化来进行新的合成。由吡咯基溴化镁和二甲基马来酸酐，然后环化，得到6，7-二甲基吲哚嗪-5，8-二酮。用马来酸酐使该方法失败。吡咯并[1,2 - b ]异喹啉-5,10-二酮可在吡咯并环中被硝化（并氧化成异喹啉-1,3,4-三酮），还原为10-羟基-3,5-二氢吡咯并[ 1,2 - b ]异喹啉-5-酮由锌和乙酸制得，并在钯/碳上氢化成10-羟基-1,2,3,5-四氢吡咯并[l，2- b] isoquinolin-5-one。二氢衍生物在空气中转化为二酮。