1-(3-Bromopropoxy)-4-fluorobenzene → 3-(4-Bromo-benzyl)-1-[3-(4-fluoro-phenoxy)-propyl]-5-methyl-1,3-dihydrobenzoimidazol-2-ylideneamine, hydrobromide salt

To a solution of 1-(4-bromo-benzyl)-6-methyl-1,3-dihydro-benzoimidazol-2-ylideneamine (0.14 g, 0.44 mmol) in 2-butanone (5 ml) at rt was added 1-(3-bromo-propoxy)-4-fluoro-benzene (0.15 g, 0.66 mmol). The reaction was stirred for 10 min and then additional 2-butanone (5 ml) was introduced. The mixture was heated to reflux where it was maintained for 48 h. After this time, the reaction was cooled to rt and additional 1-(3-bromo-propoxy)-4-fluoro-benzene (0.05, 0.22 mmol) was added. The reaction was then heated to reflux for a further 15 h. It was then cooled to rt and filtered. The collected solid was dried to provide 3-(4-bromo-benzyl)-1-[3-(4-fluoro-phenoxy)-propyl]-5-methyl-1,3-dihydrobenzoimidazol-2-ylideneamine, hydrobromide salt (0.04 g, 16%). HPLC-MS 468, 470 [M+1]+.