tert-Butanol → Ethyl 1-((tert-butoxycarbonyl)amino)cyclopropanecarboxylate

Participants

Reaction Steps

Triethylamine (29.82 mL, 214 mmol) was added under nitrogen dropwise to a mixture of 1,1-cyclopropanedicarboxylic acid monoethyl ester (31.518 g, 199 mmol), prepared in the previous step, and diphenylphosphoryl azide (47.4 mL, 219 mmol) in 40 mL of tert-butanol at room temperature. After the addition, the reaction was refluxed for 5 h. The reaction was concentrated under reduced pressure. The residue was taken up in ethyl acetate and extracted three times each with 5% citric acid, saturated NaHCO3 and saturated NaCl. The ethyl acetate layer was dried (anhydrous MgSO4), filtered and the solvent removed under reduced pressure to give 1-[[(1,1-dimethylethoxy)carbonyl]amino]cyclopropane carboxylic acid ethyl ester (41.3931 g, 91%) as a yellow oil, MS (ES) m/z 130.0 [M+H-tBoc].

Provenance & Evidence