Novel and Simple Methodology for the Synthesis of 3-Acetylindoles and their N-Alkyl Derivatives Using TBAB as Phase Transfer Catalyst

Title: Novel and Simple Methodology for the Synthesis of 3-Acetylindoles and their N-Alkyl Derivatives Using TBAB as Phase Transfer Catalyst

Volume: 8 Issue: 9

Author(s): M. Venkatanarayana and Pramod K. Dubey

Affiliation:

Keywords: 3-cyanoacetylindole, 5% aq. NaOH, 3-acetylindole, alkylating agent, phase transfer catalyst (TBAB), N-alkyl derivatives, Tetrabutylammoniumbromide, carboxamides, selfpolymerization, anhydride, nitrilium

Abstract: Using 5% aq. NaOH, a simple method for the transformation of 3-cyanoacetylindoles 2(a-e) into 3- acetylindoles 3 (a-e), in good yields, is reported. Tetrabutylammoniumbromide (TBAB) is found to be an efficient phase transfer catalyst for the synthesis of N-alkyl derivatives 5(a-t) of 3-acetylindoles 3(a-e) giving products in excellent yields. 2 (a-e) were themselves obtained from simple indoles 1 (a-e) by reaction with cyano acetic acid in the presence of propionic anhydride at 100 °C for 5-10 min. Partial hydrolysis of 2 (a-e) under hot acidic conditions yielded the corresponding carboxamides α-(3-indolecarboxoyl)acetamides 4(a-e). Which could be readily transformed into the respective 3(a-e) by refluxing with 5% aq. NaOH for 2-2.5 h.

Cite this article as:

Venkatanarayana M. and K. Dubey Pramod, Novel and Simple Methodology for the Synthesis of 3-Acetylindoles and their N-Alkyl Derivatives Using TBAB as Phase Transfer Catalyst, Letters in Organic Chemistry 2011; 8 (9) . https://dx.doi.org/10.2174/157017811799304395