ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Bimolecular reduction of 9-alkyl-3-nitrocarbazoles

J. B. Kyzioł

Institute of Chemistry, University of Opole, ul. Oleska 48, PL-45 040 Opole, Poland

E-mail: eismont@uni.opole.pl

Received: 25 January 2007  Revised: 30 April 2007  Accepted: 2 May 2007

Abstract: Reduction of 9-alkyl-3-nitrocarbazoles (Ia–Ie) with lithium aluminium hydride gave corresponding 9,9′-dialkyl-3,3′-azocarbazoles (IIa–IIe) in moderate yield. By the action of zinc dust in alcohol and aqueous alkali on I or II, 5,13-dialkyldiindolo[3,2-a,d]phenazines (IIIa–IIId) were obtained. Parent compounds, viz. 3,3′-azocarbazole (IIf) and diindolo[3,2-a,d]phenazine (IIIf) could not be obtained in these ways. Compound IIf was obtained in Vorländer reaction and IIIf by thermal decomposition of 3-azidocarbazole. Formation of IIIa–IIId is explained as a result of ortho-benzidine rearrangement of hypothetical 9,9′-dialkyl-3,3′-hydrazocarbazoles.

Keywords: nitro-to-azo reduction - benzidine rearrangement - auotoxidation

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-007-0054-z

Chemical Papers 61 (5) 398–404 (2007)