Convenient Synthesis of Substituted Aryl Cyanides and 1,1-Dicyanobenzyl Benzoate

摘要

Various substituted derivatives of benzyl cyanide such as 2,4-dichlorobenzyl cyanide 2 are important intermediates in the pharmaceutical industry (penicillin derivatives) and for the generation of a number of substances such as herbicides and pesticides. Several patents describe methods for the preparation of benzyl cyanides and the most frequently used procedure for the preparation of 2,4-dichlorobenzyl cyanide (2), involving the reaction of 2,4-dichlorobenzyl chloride (1) with NaCN or KCN (Scheme 1), is based on the general preparation of benzyl cyanides described in Organic Syntheses. The reaction is usually performed in a mixture of water and ethanol under reflux. A given method differs only in details (molar ratio of reactants, reaction time, isolation and purifying of products).