Synthesis, isolation and characterisation of fluorinated‐benzimidazoisoquinoline regioisomers

A pair of novel fluorinated-benzimidazoisoquinoline regioisomers was synthesised and isolated. Initial structural characterisation and identification employed 1D proton, 1D carbon, correlated spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond correlation (HMBC) nuclear magnetic resonance spectroscopy and mass spectrometry. However, the fluorinated regioisomers could not be differentiated using nuclear magnetic resonance (NMR) alone. Density functional theory calculations and single-crystal X-ray diffraction experiments were used to completely characterise and identify the compounds.