A method for the predominant synthesis of linear pyrroloindoles was developed, based on the attachment of the pyrrole ring to indoline and including diazo coupling of 5-and 6-aminoindolines followed by reduction, condensation with pyruvic acid ethyl ester, and indolization of the resulting 5-and 6-indolinylhydrazines. The in vitro antimicrobial, tuberculostatic, and antifungal activities of a number of 3H,6H-pyrrolo[3,2-e]indole, 1H,7H-pyrrolo[3,2-f]indole, and 1H,5H-pyrrolo[3,2-f]indole derivatives were studied. 1-(p-Chlorophenylazo)-3H,6H-pyrrolo[3,2-e]indole (XIX) and 3,5-di(p-chlorophenylazo)-1H,7H-pyrrolo[3,2-f]indole (XXIII) had high, 1-(p-nitrophenylazo)-3H,6H-pyrrolo[3,2-e]indole (XX) had moderate, and 2,7-diethoxycarbonyl-3H,6H-pyrrolo[3,2-e]indole (XVIII) had weak tuberculostatic activity. 3,5-p-Chlorophenylazo)-1H,7H-pyrrolo[3,2-f]indole (XXIII) had high activity against Gram-negative bacteria.

Convenient methods have been developed for the synthesis of derivatives of angular and linearpyrroloindoles. The first such method involves the bicyclization of m-phenylenebishydrazone of ethyl pyruvate in polyphosphates through the Fischer reaction with simultaneous formation of two pyrrole rings. The second method is based on attaching a pyrrole ring to an indoline molecule.Keywords: pyrroloindole, pyrroloindoline, m-phenylenebishydrazone of ethyl pyruvate, cyclization.Synthetic methods for pyrroloindoles now permit the preparation of similar bifunctional analogs of biologically active indole compounds [5]. Some of these compounds have bactericidal, antimicrobial, and antitumor properties [6][7][8]. The well-known natural antibiotic, CC-1065, which contains pyrroloindoline fragments, is many times more active than reported antitumor preparations [9]. Thus, the development of new synthetic methods and the synthesis of new pyrroloindole derivatives hold great interest.An angular isomer of diethoxycarbonylpyrroloindole 2 has been synthesized in 20% yield by the bicyclization of the m-phenylenebishydrazone of ethyl pyruvate (1) by heating this compound in 20% ethanolic HCl [10]. In our previous work [11], this yield was improved to 60% and compound 3, which is a linear isomer of diester 2, was obtained in 8% yield. The saponification of compounds 2 and 3 gave the corresponding diacids 4 and 5, whose decarboxylation led to angular and linear pyrroloindole isomers 6 and 7, respectively [10,11].In the present work, two methods are described for the synthesis of isomeric pyrroloindoles 6 and 7 and their derivatives, which we developed with the aim of increasing the yields of already reported and new compounds of this group.The first method is based on the abovementioned bicyclization of bishydrazone 1 according to the Fischer indole synthesis with the simultaneous formation of two pyrrole rings (Scheme 1), while the second involves the construction of a pyrrole ring in an indoline derivative (Scheme 2).Various condensing agents were studied as catalysts for the bicyclization of bishydrazone 1. Considerable tar formation occurs under rigorous conditions in the presence of ZnCl 2 , PPA, or AcOH/H 2 SO 4 . As noted above, the reaction in 20% ethanolic HCl is not very efficient [10]. A mixture of ethyl esters of PPA

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