Mantle cell lymphoma (MCL) is characterized by the translocation t(11;14) (q13;q32), resulting in the overexpression of cyclin-D1. The progression of MCL is an interaction of multitarget and multilink regulation. It has been proven that Bruton's tyrosine kinase (BTK) is commonly overexpressed in MCL, which makes it a focus of targeted therapy for MCL. Irreversible inhibitors usually have great potency, rapid onset of inhibition and long duration of drug action. Herein, structural modification via an open-loop strategy based on lead compound ibrutinib (IBN) was performed, leading to a series of pyrazole derivatives. Compounds 19c, 19'c, 21c and 21'c showed potent effect in MCL cells with IC<sub>50</sub> values lower than 1 μM, and a more than 3-28-fold increase in antiproliferative activity compared with IBN.