Synthesis and biological evaluation of 1H-pyrrolo[3,2–g]isoquinolines

[Display omitted] •New 1H-pyrrolo[3,2–g]isoquinolines were synthesized.•Haspin kinase inhibitory potency and selectivity were evaluated.•Compound 22 was active toward endogenous Haspin kinase in U-2 OS cells.•Compound 22 demonstrated anti-proliferative activity toward various cell lines.•Binding mode of analog 22 with Haspin was determined by X-ray crystallography. A structure–activity relationship study performed on 1H-pyrrolo[3,2–g]isoquinoline scaffold identified new haspin inhibitors with nanomolar potencies and selectivity indices (SI) over 6 (inhibitory potency evaluated against 8 protein kinases). Compound 22 was the most active of the series (haspin IC50 = 76 nM). Cellular evaluation of 22 confirmed its activity for endogenous haspin in U-2 OS cells and its anti-proliferative activity against various cell lines. In addition, the binding mode of analog 22 in complex with haspin was determined by X-ray crystallography.