Synthesis 2003(13): 2047-2052
DOI: 10.1055/s-2003-41019
PAPER
© Georg Thieme Verlag Stuttgart · New York

Carbonylation of Doubly Lithiated N′-Aryl-N,N-Dimethylureas: A Novel Approach to Isatins via Intramolecular Trapping of Acyllithiums

Keith Smith*, Gamal A. El-Hiti, Anthony C. HawesCentre for Clean Chemistry, Department of Chemistry, University of Wales Swansea, Singleton Park, Swansea, SA2 8PP, UK
Fax: +44(1792)295261; e-Mail: k.smith@swansea.ac.uk;
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Publication History

Received 28 May 2003
Publication Date:
19 August 2003 (eFirst)

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Abstract

Lithiation of N′-(2-bromoaryl)-N,N-dimethylureas with methyllithium and tert-butyllithium under nitrogen in anhydrous THF at 0 °C gave doubly lithiated arylurea derivatives, which react with carbon monoxide at 0 °C to give isatins in good yields. The scope of the reaction has been demonstrated by application to the synthesis of isatin itself and four substituted isatins bearing alkyl, chloro or fluoro groups.

Key words

carbonylation - N,N-dimethylureas - isatins - intramolecular trapping - positron emission tomography