On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of Carbazoles

Carbazole (1) undergoes electrophilic aromatic substitution with various chlorinating reagents. Although 3-chlorocarbazole (1b), 3,6-dichlorocarbazole (1d) and 1,3,6,8-tetrachlorocarbazole (1f) obtained by chlorination of carbazole were isolated and characterized sometime ago, 1-chlorocarbazole (1a)...

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Autores principales: Bonesi, S.M., Erra-Balsells, R.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0022152X_v34_n3_p877_Bonesi
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_0022152X_v34_n3_p877_Bonesi2023-10-03T14:27:42Z On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of Carbazoles Bonesi, S.M. Erra-Balsells, R. Carbazole (1) undergoes electrophilic aromatic substitution with various chlorinating reagents. Although 3-chlorocarbazole (1b), 3,6-dichlorocarbazole (1d) and 1,3,6,8-tetrachlorocarbazole (1f) obtained by chlorination of carbazole were isolated and characterized sometime ago, 1-chlorocarbazole (1a), 1,6-dichlorocarbazole (1c) and 1,3,6-trichlorocarbazole (1e) had never been isolated from the reaction mixtures. The preparation and subsequent isolation and characterization of 1a, 1b, 1e, 1d, 1e and 1f are reported (mp, tF, Rf, 1H- and 13C-nmr, ms). Physical and spectroscopic properties of le are compared with those of 1b and 1d in order to show that the former is the major product obtained in several chlorinating processes. As chlorinating reagents, chlorine in glacial acetic acid, sulfuryl chloride, N-chlorosuccinimide, N-chlorosuccinimide-silica gel, N-chlorobenzotriazole, and N-chlorobenzotriazole-silica gel in dichloromethane and in chloroform have been used and their uses have been compared. The chlorination reaction of different carbazole derivatives such as 2-hydroxycarbazole (2), 2-acetoxycarbazole (3), 3-bromocarbazole (4) and 3-nitrocarbazole (5) was also studied and the corresponding chloro derivatives 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d, 3e, 3f, 4a, 4b, 4c, 4d, 5a and 5b are described for the first time. Semiempirical PM3 calculations have been performed in order to predict reactivity of carbazole (1), substituted carbazoles 2-5 and chlorocarbazoles (Scheme 1). Theoretical and experimental results are discussed briefly. Fil:Bonesi, S.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Erra-Balsells, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0022152X_v34_n3_p877_Bonesi
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description Carbazole (1) undergoes electrophilic aromatic substitution with various chlorinating reagents. Although 3-chlorocarbazole (1b), 3,6-dichlorocarbazole (1d) and 1,3,6,8-tetrachlorocarbazole (1f) obtained by chlorination of carbazole were isolated and characterized sometime ago, 1-chlorocarbazole (1a), 1,6-dichlorocarbazole (1c) and 1,3,6-trichlorocarbazole (1e) had never been isolated from the reaction mixtures. The preparation and subsequent isolation and characterization of 1a, 1b, 1e, 1d, 1e and 1f are reported (mp, tF, Rf, 1H- and 13C-nmr, ms). Physical and spectroscopic properties of le are compared with those of 1b and 1d in order to show that the former is the major product obtained in several chlorinating processes. As chlorinating reagents, chlorine in glacial acetic acid, sulfuryl chloride, N-chlorosuccinimide, N-chlorosuccinimide-silica gel, N-chlorobenzotriazole, and N-chlorobenzotriazole-silica gel in dichloromethane and in chloroform have been used and their uses have been compared. The chlorination reaction of different carbazole derivatives such as 2-hydroxycarbazole (2), 2-acetoxycarbazole (3), 3-bromocarbazole (4) and 3-nitrocarbazole (5) was also studied and the corresponding chloro derivatives 2a, 2b, 2c, 2d, 3a, 3b, 3c, 3d, 3e, 3f, 4a, 4b, 4c, 4d, 5a and 5b are described for the first time. Semiempirical PM3 calculations have been performed in order to predict reactivity of carbazole (1), substituted carbazoles 2-5 and chlorocarbazoles (Scheme 1). Theoretical and experimental results are discussed briefly.
format JOUR
author Bonesi, S.M.
Erra-Balsells, R.
spellingShingle Bonesi, S.M.
Erra-Balsells, R.
On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of Carbazoles
author_facet Bonesi, S.M.
Erra-Balsells, R.
author_sort Bonesi, S.M.
title On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of Carbazoles
title_short On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of Carbazoles
title_full On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of Carbazoles
title_fullStr On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of Carbazoles
title_full_unstemmed On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of Carbazoles
title_sort on the synthesis and isolation of chlorocarbazoles obtained by chlorination of carbazoles
url http://hdl.handle.net/20.500.12110/paper_0022152X_v34_n3_p877_Bonesi
work_keys_str_mv AT bonesism onthesynthesisandisolationofchlorocarbazolesobtainedbychlorinationofcarbazoles
AT errabalsellsr onthesynthesisandisolationofchlorocarbazolesobtainedbychlorinationofcarbazoles
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