Di-tert-butyl dicarbonate → HCID 68513291, compound

Participants

Reaction Conditions

Reaction Steps

4-[2-(2,2-Diethoxy-propionylamino)-4-methyl-phenylamino]-piperidine-1-carboxylic acid tert-butyl ester (500 mg, 1.11 mmol) was dissolved in glacial acetic acid (5 mL), and the mixture was heated at 90° C. overnight. The mixture was cooled, concentrated under reduced pressure. The resulting residue was partitioned between CH2Cl2 (50 mL) and dilute aqueous K2CO3 solution. The organic layer was separated, and the aqueous layer was extracted with CH2Cl2 (2×25 mL). The combined organic layers were dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated to approximately 30 mL, and di-tert-butyldicarbonate (218 mg, 1 mmol) and DMAP (5 mg, 0.04 mmol) were added. The mixture was stirred overnight at rt, washed with saturated aqueous NH4Cl solution and dried over anhydrous Na2SO4. The mixture was concentrated, and the residue was purified by flash chromatography (30% ethyl acetate in hexanes) to give 4-(2-acetyl-5-methyl-benzoimidazol-1-yl)-piperidine-1-carboxylic acid tert-butyl ester (270 mg, 0.756 mmol, 68%) as a waxy solid.

Provenance & Evidence