SYNTHESIS OF 2-CARBOXY-5,6-ETHYLENEDIOXYINDOLE AND ITS 3-, 4-, AND 7-HALO DERIVATIVES

Article abstract of DOI:10.1007/BF00513435

A method for the synthesis of 2-carboxy-5,6-ethylenedioxyindole and its 4- and 7-chloro derivatives from 3,4-ethylenedioxyaniline and, correspondingly, its 2- and 5-chloro derivatives via Fischer reaction was developed.It was established that in the case of bromination or chlorination under mild conditions 2-carbethoxy-5,6-ethylenedioxyindole forms 3-halo derivatives, while 5,6-ethylenedioxyindole itself forms only 3,7-dihalo derivatives.The closeness in the reactivities of the 3 and 7 ring positions of 5,6-ethylenedioxyindole (as compared with indole) is in agreement with the results of calculations of the quantum-chemical reactivity indexes for electrophilic substitution.