Preparation method of amide

The invention discloses a preparation method of amide. With an aldehyde derivative and a formamide derivative as a reaction substrate, iodide as catalyst and tert-butanol hydrogen peroxide as an oxidizing agent, the amide is prepared through decarbonylation double free radical cross-coupling reaction, wherein the chemical structural formula of the aldehyde derivative is shown in the description, R1 is selected from a naphthyl, a heterlcyclic ring, an alkylene or a mono-substituted aryl; and the iodide is one selected from sodium iodide, potassium iodide, cuprous iodide, lithium iodate, an iodine elementary substance, tetrabutyl ammonium iodide, tetraheptylammonium iodide, tetramethylammonium iodide and benzyltrimethylammonium iodide. According to the invention, because the amide is prepared by using the iodide as the catalyst and using the double free radical cross-coupling method, the use of the traditional metal catalyst with expensive price and larger toxicity as well as a complicated experiment method is avoided so that the reaction is simpler, more convenient, easier, safer, greener and more economic; moreover, the preparation method of the amide disclosed by the invention has the advantages of quite moderate reaction condition, simpler post-treatment and potential industrial application value.