Design, synthesis and biological evaluation of 2,3-dihydroimidazo[2,1-b]thiazoles as dual EGFR and IGF1R inhibitors.

Abstract Herein we describe the design, synthesis and anticancer evaluation of a series of 2,3-dihydroimidazo[2,1-b]thiazoles as dual kinase inhibitors of IGF1R and EGFR. A series of saturated dihydroimidazo[2,1-b] thiazoles were synthesized to understand the structure–activity relationship. Further, the key modifications were performed to improve drug like properties of the series. A 2-oxa-6-azaspiro [3.3] heptane moiety was incorporated as a bioisosteric replacement of morpholine on dihydroimidazo[2,1-b] thiazole scaffold.Subsequent structure–activity relationship (SAR) studies identified several compounds with nM range of activity. The compound 18a shows promising activity, IC50 = 52 nM against IGF1R and IC50 = 35.5 nM against EGFR with descent PK profile. The identified leadshows promising activity against both wild type and the T790M mutant forms of enzymes.