INFLUENCE OF THE CYANO GROUP ON ORIENTATION OF NUCLEOPHILES TO ARYNE .1. REACTION OF ISOMERIC HALOBENZONITRILES WITH ALKALI AMIDES IN LIQUID-AMMONIA

The reaction of either 0- or m-bromobenzonitrile with 2 equiv of lithium amide, sodium amide, or potassium amide yields aminobenzonitriles in a ratio of 95:5 meta/ortho, respectively. Similarly, p-bromobenzonitrile gives aminobenzonitriles in a ratio of 80:20 para/meta, respectively. These ratios are in a range which would be expected for the cyano group influencing amination orientation to aryne by the inductive mode. In the presence of 4 equiv of potassium amide, the meta/ortho and para/meta aminobenzonitrile ratios obtained from the corresponding bromobenzonitrile are 89:11 and 95:5, respectively. These altered ratios do not reflect a change in the orienting effect of the cyano group, but rather the instability of the aminobenzonitriles in highly basic medium. Similar results are observed for the reaction of the isomeric iodobenzonitrile with the exception of o-iodobenzonitrile, which is predominantly reduced by alkali amide. The reaction of the isomeric chloro- and fluorobenzonitriles yield aminobenzonitrile in very low yields, the predominant product being the corresponding chloro- or fluo-robenzoamidine. An explanation in terms of the relative rates of formation of aryne and amidine is presented. © 1979, American Chemical Society. All rights reserved.