Water → 3-(3-Bromobenzyl)-2-oxo-1-oxa-3,8-diazaspiro[4.5]decane-8-carboxylic acid tert-butyl ester

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Reaction Steps

Sodium hydride (246 mg, 60% dispersion in mineral oil, weight percent) was suspended under a nitrogen atmosphere in DMF (15 mL). Compound A3 (1.5 g, 5.85 mmol) was added thereto and the reaction mixture was stirred for 10 min at RT. 3-Bromobenzyl bromide (1.48 g, 5.91 mmol) was added thereto. The reaction mixture was stirred for 18 h at RT, combined with water and extracted with EtOAc. The combined organic phases were washed with sat. aq. NaCl solution, dried over Na2SO4 and the solvent was removed under a vacuum. The residue was dissolved in a mixture of ether and heptane. After removal of the ether, the desired product 3-(3-bromobenzyl)-2-oxo-1-oxa-3,8-diazaspiro[4.5]decane-8-carboxylic acid tert-butyl ester (A6) (2.33 g, 93% of theoretical) was obtained as a white solid by filtration.

Provenance & Evidence