Acetic Acid → 7-(2-{1-[2-(4-Cyanophenoxy)ethyl]-3,3-dimethylureido}ethyl)-9-oxa-3,7-diazabicyclo[3.3.1]nonane-3-carboxylic acid tert-butyl ester

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Reaction Steps

1-[2-(4-Cyanophenoxy)ethyl]-3,3-dimethyl-1-(2-oxoethyl)urea (4.5 g; see Preparation G above) was taken in dichloromethane (100 mL). 9-Oxa-3,7-diazabicyclo[3.3.1]nonane-3-carboxylic acid tert-butyl ester (2.9 g, 0.013 mol; see WO 01/28992), followed by glacial acetic acid (1.47 g, 0.0245 mol), was added, and reaction mixture was stirred for 1 h. NaBH3CN (1.54 g, 0.024 mol) was added at 0° C., and stirring was continued overnight at room temperature. The reaction mixture was diluted with water and extracted with dichloromethane. The organic layer was washed with water and brine and then dried over sodium sulfate. Solvent evaporation, followed by purification by column chromatography, yielded the title compound (6.5 g).

Provenance & Evidence