Method for catalytic conversion of cyano group into deuterated methyl, prepared aromatic deuterated methyl compound and application of compound

The invention provides a method for catalytic conversion of a cyano group into deuterated methyl, a prepared aromatic deuterated methyl compound and an application of the compound. The method comprises the steps as follows: an aromatic cyano compound reacts to produce the aromatic deuterated methyl compound under the action of a metal catalyst with deuterium gas serving as a deuterium source. The cyano group is directly catalyzed into deuterated methyl with the deuterium gas serving as the deuterium source, the operation is simple, the raw material is cheap and easy to obtain, the reaction yield is high, the product deuteration rate is high, and the method can be applied to mass production. The prepared aromatic deuterated methyl compound can be used as a deuterated medicine or can be used for preparation of a deuterated medicine or deuterated medicine composition, and the pharmacokinetics, pharmacodynamics or metabolism toxicity of the medicine can be reduced while the medicine molecular activity is kept unc