N-Substituted halogenomethyleneindoxyls

摘要

Novel N-substituted halogenomethyleneindoxyls [N-substituted halogeno-(3-oxa[2H]indol-2-ylidene)-acetic acids] and a novel process for their preparation by reacting N-substituted anilides with dihalogenomaleic anhydrides or derivatives thereof are described. The novel N-substituted halogenomethyleneindoxyls are valuable intermediates for the preparation of pharmaceutical active compounds having an antiallergic action.