Cesium carbonate → [1-(2-(4-Biphenyl-2-ylmethyl-piperazin-1-yl)-benzyl]-3-[3-(4-fluoro-phenoxy)-propyl]-1,3-dihydro-benzoimidazol-ylidene]-carbamic acid tert-butyl ester

Participants

Reaction Steps

To a degassed solution of [1-(2-bromo-benzyl)-3-[3-(4-fluoro-phenoxy)-propyl]-1,3-dihydro-benzoimidazol-ylidene]-carbamic acid tert-butyl ester (200 mg, 0.36 mmol) in anhydrous toluene (4 ml) was added Pd(OAc)2 (0.7 mg, 1.8 □mol). Nitrogen was bubbled through the suspension for 10 min before BINAP (17 mg, 27 □mol) was added. After a further 2 min 1-biphenyl-2-ylmethyl-piperazine (99 mg, 0.36 mmol) in degassed toluene (4 ml) was introduced and then after a additional 2 min Cs2CO3 (0.86 g, 2.6 mmol) was added and the reaction was stirred for 2 min. Throughout all of the additions nitrogen was continuously bubbled through the reaction mixture. To After 2.75 h the reaction was cooled to rt and filtered through Celite®. Purification by chromatography on silica gave [1-[2-(4-biphenyl-2-ylmethyl-piperazin-1-yl)-benzyl]-3-[3-(4-fluoro-phenoxy)-propyl]-1,3-dihydro-benzoimidazol-ylidene]-carbamic acid tert-butyl ester (100 mg) which was used without purification in the next step.

Provenance & Evidence