Preparation method of mepivacaine and optical enantiomer of mepivacaine

The invention discloses a novel preparation method of mepivacaine and an optical enantiomer of the mepivacaine. The method comprises the steps of taking N-(2,6-dimethyl phenyl)-2-piperidinecarboxamide or an optical enantiomer thereof as a starting material, taking formaldehyde as a methylation reagent, stirring in formic acid at 60-100 DEG C for reaction, and obtaining the mepivacaine or the optical enantiomer thereof. The raw materials adopted with the method are commercially available, extensive and sufficient in source and low in price, reaction conditions of the method are mild, a process is simple, and the disadvantages that hazardous reagents such as dimethyl sulfate and sodium cyanoborohydride are used and anhydrous reaction conditions are required are avoided.