Benzyl Alcohol → 3-Benzyloxycarbonylamino-3-(1-methylallyl)piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a refluxed solution of an optically-active compound of 3-(1-methylallyl)piperidine-1,3-dicarboxylic acid 1-tert-butyl ester (9.0 g) and triethylamine (8.9 ml) in toluene (90 ml) was added dropwise diphenylphosphoryl azide (8.9 ml) over 25 minutes. The reaction mixture was stirred for 2.5 hours at the same temperature, and then thereto were added benzyl alcohol (10 ml) and 4-dimethylaminopyridine (771 mg). The mixture was stirred for 33 hours with refluxing, followed by cooled to room temperature, and acidified by the addition of 10% aqueous potassium bisulfate solution. The mixture was extracted with ethyl acetate, and the organic layer was washed with saturated aqueous sodium chloride solution and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent: chloroform/acetone=20/1). The fractions which could not be isolated or purified were concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (eluent: chloroform/acetone=20/1) again. The purified fractions are combined to be concentrated under reduced pressure to give the titled compound (11.0 g).

Provenance & Evidence