The synthesis of pyrrolo[1,2-b][1,2,5]benzothiadiazepines from 1,2-thiazine 1-oxides - Sulfonamide analogues of the pyrrolobenzodiazepine antitumour natural products

Karl Hemming, Nilesh Patel

Research output: Contribution to journalArticle

19 Citations (Scopus)


Pyrrolo[2,1-c][1,4]benzodiazepines (PBDs) and the corresponding pyrrolobenzothiadiazepines (PBTDs) are attractive targets as natural and synthetic antitumour antibiotics and as non-nucleosidic reverse transcriptase inhibitors. A concise synthesis of the PBTD class is presented, which starts from o-azidobenzenesulfonamide and its conversion into 2-(o- azidobenzenesulfonyl)-1,2-thiazine 1-oxides via Diels-Alder reaction. After a one-pot ring contraction, desulfurisation and aromatisation process, accompanied by concomitant same pot conversion of the azide group into a primary amine via the Staudinger reaction, these 1,2-thiazine-1-oxides yield a 1-(o-aminobenzenesulfonyl)pyrrole. N-Formylation of the amine and Bischler-Napieralski ring closure onto the pyrrole completes the PBTD synthesis.

Original languageEnglish
Pages (from-to)7553-7556
Number of pages4
JournalTetrahedron Letters
Issue number41
Early online date11 Sep 2004
Publication statusPublished - 4 Oct 2004


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