A Versatile Approach for the Synthesis of 8H‐Thieno[2,3‐b]indoles and N‐[2‐(2‐N‐(R₁,R₂)‐2‐Thioxoacetyl)‐phenyl]acetamides from 1‐Acetyl‐1,2‐dihydro‐3H‐indol‐3‐one (Acetylindoxyl) and Its Derivatives: A Novel Synthesis of Intermediate (1‐Acetyl‐1H‐indol‐3‐yl)malononitrile/cyanoacetates

Abstract

We report on two approaches for the synthesis of new 2‐amino‐3‐cyano/alkoxycarbonyl‐8H‐thieno[2,3‐b]indoles 5 and another one for the synthesis of 2‐N,N‐dialkylamino‐3‐cyano/aryl‐8H‐thieno[2,3‐b]indoles 16, based either on acetylindoxyl 1 and (1‐acetyl‐1H‐indol‐3‐yl)malononitrile/cyanoacetates 14 or 2‐bromoacetylindoxyl 2 transformations. A new, simple, rapid, and efficient method for the synthesis of valuable key intermediate malononitrile/cyanoacetates 14 based on acetylindoxyl 1 condensation with malononitrile or cyanoacetates in the presence of triethylamine has been developed. A number of synthetic procedures for the preparation of thioacetamides 6, 1‐acetylthioisatin 8, and 2,2‐disubstituted indoxyls 13 have been elaborated during the synthesis of thieno[2,3‐b]indoles. Thioacetamides 6 have been shown as novel agents active against Mycobacterium tuberculosis H37Rv, the cause of tuberculosis, with minimal inhibitory concentration values ranging between 5 and 21 μg/mL.

Design, Synthesis, and Anticancer Activity of Novel Benzothiazole Analogues

“…It is well documented that Gewald multicomponent reaction of activated nitriles with ketones and elemental sulfur in the presence of a basic catalyst led to the synthesis of the corresponding aminothiophene derivatives through the formation of non‐isolated acrylonitrile intermediate .…”

Isatin Derivatives with Potential Antitubercular Activities

“…Several miscellaneous isatin derivatives were also screened for their anti‐TB activities by different research groups . Some of them such as 55a–c (MIC: 1.56 μg/mL against MTB H37Rv) , 56 (MIC: 6.25 μg/mL against MTB H37Rv) , and isatin‐lamivudine hybrids 57 (inhibited 92–100% growth of MTB H37Rv at 6.25 μg/mL) (Fig.…”

Dihydropyrrole-3-thiones: one-pot synthesis from propargylamines, acyl chlorides and sodium sulfide

“…16 It should be especially emphasized that research in the field of pyrrolethione chemistry is mainly focused on the use of indolylthiones and their analogues with a thione group at position 2 of the heterocyclic core. [2][3][4][5][6][7][8][9][10][11][12][13][14] At the same time, the syntheses of pyrroles with a CvS fragment at position 3 have been described just sporadically. 17 In addition, obtaining pyrrole-3ones ( pyrrole-3-thione precursors) is also a separate complex synthetic task due to the fact that the main methods for their synthesis are laborious and involve multiple steps.…”

“…1). 2–12 For example, ammosamide A (a natural alkaloid) with a pyrrole-2-thione fragment showed significant in vitro cytotoxicity against HCT-116 colon carcinoma. 3 Natural phytoalexins, such as brassilexin, sinalexin and wasalexin, showing fungicidal properties were synthesized based on pyrrole-2-thiones.…”