Preparation process of ibrutinib

The invention discloses a preparation process of ibrutinib. According to the technical scheme, the preparation process is characterized by comprising the following steps: S1, cyclization reaction: cyclizing 3-amino-5-(4-phenoxy phenyl)-4-cyano-1H-pyrazole and formamide under the catalytic action of ammonium formate to form an intermediate I; s2, Mitsunobu reaction: carrying out Mitsunobu reaction on the intermediate I by adopting a one-pot method to obtain an intermediate II, and further carrying out acid deprotection to obtain an intermediate III; s3, salifying reaction: salifying the intermediate III in hydrochloric acid isopropanol to obtain an intermediate IV; and S4, acylation reaction: reacting the intermediate IV with acryloyl chloride in the presence of an acid-binding agent to obtain the final product ibrutinib. According to the method, the reaction steps are simplified, and reagents used in the whole process are low in toxicity, so that the use of high-toxicity solvents is avoided, meanwhile, the to