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1. (WO2001038333) PRODUCTION OF DISUBSTITUTED PENTAFULVENS VIA LITHIATED SILYL-(HALO)ARENE INTERMEDIATES

Pub. No.:    WO/2001/038333    International Application No.:    PCT/US2000/031493
Publication Date: Fri Jun 01 01:59:59 CEST 2001 International Filing Date: Thu Nov 16 00:59:59 CET 2000
IPC: C07F 7/08
Applicants: ALBEMARLE CORPORATION
Inventors: BERRIS, Bruce, C.
OWENS, David, W.
MATHUR, Rajeer, S.
Title: PRODUCTION OF DISUBSTITUTED PENTAFULVENS VIA LITHIATED SILYL-(HALO)ARENE INTERMEDIATES
Abstract:
Lithiated haloarenes, although useful as intermediates in the synthesis of various end products, can be hazardous to prepare since unstable, shock sensitive compounds can be formed during lithiation of haloarenes. To avoid this problem, a reaction of a polyhaloarene with a hydrocarbyl lithium compound is conducted in the presence of another reactant so that the lithiated haloarene, if formed at all, exists as a transitory intermediate in low concentration. In this way, transitory lithiated haloarene which may be, and presumably is, formed in the reaction is converted into a non-hazardous functionally-substituted haloarene essentially as soon as such lithiated haloarene is formed. Thus, an arene having a halogen atom of atomic number greater than 9 substituted on at least two non-adjacent carbon atoms is concurrently reacted with a non-fluoro halotrihydrocarbylsilane and a hydrocarbyl lithium compound, in proportions such that a haloarene having at least one trihydrocarbylsilyl ring substituent is formed.