Preparation method of 3-alkenyl-1H-indazole compound

The invention discloses a preparation method of a 3-alkenyl-1H-indazole compound. The preparation method comprises the following steps: 1, carrying out a reaction of 3-triazenylaryl substituted allyl alcohol or 1-triazenylaryl cinnamyl alcohol in a solvent under the action of an acid catalyst to obtain a 2-pyrryl-3-alkenyl-2H-indazole compound; and 2, removing the pyrryl group from the 2-pyrryl-3-alkenyl-2H-indazole compound obtained in step 1 under the action of a reducing agent to obtain the 3-alkenyl-1H-indazole compound. The preparation method avoids the use of a metal catalyst, avoids the tedious and expensive raw material preparation process, and has the characteristics of mild reaction conditions, and concise and convenient operation.