Potassium Carbonate → 7-(2-{1-[2-(4-Cyanophenoxy)ethyl]ureido}ethyl)-9-oxa-3,7-diazabicyclo-[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]-ureido}ethyl ester (15 g, 0.0372 mol, 1.0 eq.; see Preparation D above), 9-oxa-3,7-diaza-bicyclo[3.3.1]nonane-3-carboxylic acid tert-butyl ester (8.525 g, 0.0372 mol, 1.0 eq.; see WO 01/28992), fused K2CO3 (7.7 g, 0.0558 mol, 1.5 eq.) and lithium bromide (9.6 g, 0.1116 mol, 3.0 eq.) in dry acetonitrile (350 mL) was heated to 40° C. under N2 for 4 days. The reaction was cooled to rt, filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by column chromatography over silica gel, using 3% methanol and DCM as eluent, to yield the sub-title compound as a white solid. Yield: 7 g, 40.9%.

Provenance & Evidence