CuBr2 - an effective catalyst in the synthesis of amides from secondary alcohols by the Ritter reaction

The Ritter reaction is widely used in the synthesis of antiallergic, antibiotic, antitumor, antibacterial, influenza antiviral, antiproliferative and antimicrobial drugs. In this regard, the search for new effective catalysts for the synthesis of amidesin mild conditions is an urgent task. Of particular interest is the use of an alcohol as a second substrate. We were the first to carry out the CuBr2-catalyzed reaction of acetonitrile with secondary alcohols such as 2-propanol, 2-butanol, cyclohexanol, cyclopentanol, 2-phenylethanol and adamantanol-2, which gives the corresponding amides in 80-100% yield. CuBr2-Catalyzed reaction of cyclohexanol with a number of nitriles (MeCN, EtCN, PhCN, o-MeC6H4CN) was studied. It was found that the reaction of cyclohexanol with nitriles in the presence of CuBr2 proceeds in three directions giving dicyclohexyl ether, amides and esters (in particular, cyclohexyl acetate and cyclohexyl propionate) depending on the reaction conditions, catalyst concentration and the nature of the nitrile. The methodology we have discovered opens up prospects for the use of copper catalysis in the synthesis of practically useful amides.