Nucleophilic substitution process

摘要

2-(Fluoronitrobenzene)alkyl cyanides are prepared by reacting a fluoronitrobenzene with an alpha-substituted alkyl cyanide in a substantially anhydrous aprotic solvent and in the presence of a base so that the alkyl cyanide reactant undergoes a nucleophilic substitution reaction on an unsubstituted carbon atom of the fluoronitrobenzene during which the alpha-substituent of the alkyl cyanide reactant functions as a leaving group. Use of 2-fluoronitrobenzene and an alpha-substituted propionitrile (e.g., 2-chloropropionitrile) produces a novel compound, 2-(3-fluoro-4-nitrobenzene)propionitrile. Reduction of the nitro substituent produces another novel compound, 2-(4-amino-3-fluorobenzene)proprionitrile. This can readily be converted to 2-(3-fluoro-4-biphenylyl)propionitrile by means of a Gomberg-Bachmann reaction with an aromatic hydrocarbon or substituted aromatic hydrocarbon which in turn can be converted on hydrolysis into the corresponding 2-(2-fluoro-4-biphenylyl)propionic acid. Use of benzene in the Gomberg-Bachmann reaction thus enables production of flurbiprofen, a well-known pharmaceutical.