Potassium Carbonate → 7-(2-{1-[2-(4-Cyanophenoxy)ethyl]-3-methylureido}ethyl)-9-oxa-3,7-diaza-bicyclo[3.3.1]nonane-3-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of toluene-4-sulfonic acid 2-{1-[2-(4-cyanophenoxy)ethyl]-3-methylureido}ethyl ester (1.35 g, 3.233 mmol; see Preparation I above), 9-oxa-3,7-diaza-bicyclo[3.3.1]nonane-3-carboxylic acid tert-butyl ester (1.48 g, 6.466 mmol; see WO 01/28992) and potassium carbonate (1.34 g, 9.7 mmol) in dry acetonitrile (15 mL) was stirred at 45° C. for 24 h. The reaction mixture was diluted with 20 mL water and extracted with ethyl acetate. The organic layer was washed with water, brine and dried over sodium sulfate. Solvent evaporation under reduced pressure followed by column chromatography over silica gel (using 2-2.5% methanol in dichloromethane) and further purification by preparative HPLC yielded 920 mg of the title compound as a white solid.

Provenance & Evidence