A “Catch–React–Release” Method for the Flow Synthesis of 2-Aminopyrimidines and Preparation of the Imatinib Base

The development of a monolith-supported synthetic procedure is reported, taking advantage of flow processing and the superior flow characteristics of monolithic reagents over gel-phase beads, to allow facile access to an important family of 2-aminopyrimidine derivatives. The process has been successfully applied to a key precursor on route to Imatinib (Ar = 3-pyridyl, R1 = 2-methyl-5-nitrobenzyl, R2 = H).