Exchange Reactions of Deuterated Benzene Derivatives with Potassium Amide in Liquid Ammonia

The rates of deuterium-protium exchange have been determined for o-, m- and p-deuterated fluorobenzene, benzotri-fluoride and anisole in liquid ammonia solution in the presence of potassium amide. The exchange rates were found to be greatest for the ortho compounds and smallest for the para compounds. Deuterobenzene and o-deuterotoluene reacted too slowly for convenient measurement. The results are interpreted on the basis of the operation of combined inductive and field effects of the substituents, mesomeric effects appearing to be of minor importance.