5-bromo-2-formyl-N,N-dimethylbenzamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 100 mL round-bottom flask was charged with tert-butyl piperazine-1-carboxylate (86.0 mg, 0.460 mmol, 1.00 equiv), 5-bromo-2-formyl-N,N-dimethylbenzamide (130 mg, 0.510 mmol, 1.10 equiv), dichloromethane (10 mL). Triethylamine (139 mg, 1.37 mmol, 3.00 equiv) was added. The mixture was stirred for 30 min at room temperature. Sodium triacetoxyborohydride (293 mg, 1.38 mmol, 3.00 equiv) was added. The resulting solution was stirred overnight at room temperature, diluted with water (15 mL), extracted with dichloromethane (3×15 mL) and the organic layers were combined, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (50/50) to provide 170 mg (87% yield) of tert-butyl 4-[[4-bromo-2-(dimethylcarbamoyl)phenyl]methyl]piperazine-1-carboxylate as light yellow oil. LCMS (ESI, m/z): 426 [M+H]+. The resulting solution was stirred overnight at room temperature extracted with dichloromethane (3×15 mL) dried over Na2SO4 filtered concentrated under reduced pressure The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (50/50)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 100 mL round-bottom flask was charged with 5-bromo-2-formylbenzoic acid (350 mg, 1.53 mmol, 1.00 equiv), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (355 mg, 1.85 mmol, 1.20 equiv), 1-hydroxybenzotrizole (315 mg, 2.33 mmol, 1.50 equiv), dichloromethane (10 mL). The resulting solution was stirred for 15 min at room temperature. Dimethylamine (208 mg, 4.61 mmol, 3.00 equiv) was added. The resulting solution was stirred overnight at room temperature, diluted with water (20 mL), extracted with dichloromethane (3×20 mL) and the organic layers were combined, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (50/50) to provide 86.0 mg (22% yield) of 5-bromo-2-formyl-N,N-dimethylbenzamide as light yellow oil. LCMS (ESI, m/z): 256 [M+H]+. The resulting solution was stirred overnight at room temperature extracted with dichloromethane (3×20 mL) dried over Na2SO4 filtered concentrated under reduced pressure The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (50/50)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 100 mL round-bottom flask was charged with 5-bromo-2-formylbenzoic acid (350 mg, 1.53 mmol, 1.00 equiv), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (355 mg, 1.85 mmol, 1.20 equiv), 1-hydroxybenzotrizole (315 mg, 2.33 mmol, 1.50 equiv), dichloromethane (10 mL). The resulting solution was stirred for 15 min at room temperature. Dimethylamine (208 mg, 4.61 mmol, 3.00 equiv) was added. The resulting solution was stirred overnight at room temperature, diluted with water (20 mL), extracted with dichloromethane (3×20 mL) and the organic layers were combined, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (50/50) to provide 86.0 mg (22% yield) of 5-bromo-2-formyl-N,N-dimethylbenzamide as light yellow oil. LCMS (ESI, m/z): 256 [M+H]+. The resulting solution was stirred overnight at room temperature extracted with dichloromethane (3×20 mL) dried over Na2SO4 filtered concentrated under reduced pressure The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (50/50)