Dicyclohexylcarbodiimide → (R)-((R)-quinuclidin-3-yl) 2-(tert-butoxycarbonylamino)-2-phenylacetate

A mixture of (R)-2-(tert-butoxycarbonylamino)-2-phenylacetic acid (1.00 g, 3.98 mmol), (R)-quinuclidin-3-ol (0.51 g, 3.98 mmol), 1H-benzo[d][1,2,3]triazol-1-ol (0.64 g, 4.78 mmol), and DCC (0.98 g, 4.78 mmol) was stirred at RT overnight. Then THF was removed by vacuum, and the residue was partitioned between EtOAc and 2M K2CO3. The organic phase was dried over Na2SO4, filtered, and evaporated to dryness. The crude was purified by flash chromatography (DCM/MeOH=98/2 to 95/5) to obtain (R)—((R)-quinuclidin-3-yl) 2-(tert-butoxycarbonylamino)-2-phenylacetate (612 mg; 43% yield).