Diphenylacetonitrile, reduction

Diphenylacetic acid has been obtained by the reduction of benzilic acid with hydriodic acid and red phosphorus 1 by the treatment of phenylbromoacetic acid with benzene and zinc dust,2 or with benzene and aluminum chloride 3 by the hydrolysis of diphenylacetonitrile 4 by heating a-diphenyldichloroethyl-ene with alcoholic sodium ethylate 5 by heating benzilic acid 6 from diphenylmethane, mercury diethyl, sodium and carbon dioxide 7 by the oxidation of a,a,5,S-tetraphenyl- 8-butine 8 by the decomposition of some complex derivatives obtained from diphenylketene 9 by the hydrolysis of diphenyl-5,5-hydan-toin 10 by the treatment of diphenylbromoacetic acid with copper 11 by the oxidation of dichlorodiphenylcrotonic acid.12... 

A sodium hydroxide/polyethylene glycol system was used in the reductive decya-nation of diphenylacetonitriles to give diphenylmethanes in high yield. Thermal reaction times of 60 min could be reduced to 2 min under microwave irradiation (Scheme 4.43)69. 

Bendale, P.M., Chowdhury, B.R. and Khadilkar, B.M., Polyethylene glycol mediated reductive decyanation of diphenylacetonitrile moderately enhanced by microwave heating, Indian]. Chem., Sect. B, 2001,40,433—435. 

Iron pentacarbonyl in boiling dibutyl ether converts primary thioamides to nitriles [47] in moderately good yields, for example, m-toluonitrile (66%), ben-zonitrile (64%). Reduction of a carboxamide by sodium borohydride requires fairly drastic conditions [48] but if the amide is first converted into the imino-ether by means of Meerwein s reagent and this is then treated with the reducing agent in ethanol at 60°, a good yield of the nitrile is obtained replacing the borohydride by sodium ethoxide raises the yield appreciably [49], for example, benzonitrile (95%), pentanenitrile (90%), 2,2-dimethylpropanenitrile (86%), diphenylacetonitrile (100%). 

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