Diisopropylethylamine → HCID 57951460, compound

Participants

Reaction Steps

3-Phenyl-1-oxa-2-azaspiro[4.5]dec-2-ene-8-carboxylic acid (400 mg, 1.54 mmol) was slowly added to a solution of N-ethyldiisopropylamine (662 g, 4.6 mmol), 1-hydroxybenzotriazole hydrate (206 mg, 1.54 mmol), O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (496 mg, 1.54 mmol) and N-(4-aminomethyl-2-fluorophenyl)methanesulphonamide (336 mg, 1.54 mmol) in abs. THF (11 ml). The reaction mixture was stirred overnight and the solvent removed under vacuum. The residue was taken up in EtOAc (75 ml). The precipitate formed was removed by suction-filtration, washed with a small amount of ether and dried. The desired product 3-phenyl-1-oxa-2-azaspiro[4.5]dec-2-ene-8-carboxylic acid-3-fluoro-4-methanesulphonylaminobenzylamide was obtained as a cis isomer (89 mg, 13% of the theoretical amount). The organic phase was washed successively with sat. aq. NaCl solution, sat. aq. NaHCO3 solution, sat. aq. ammonium sulphate solution and sat. aq. NaCl solution, dried over magnesium sulphate and the solvent removed under vacuum. The residue was boiled up in EtOAc (2.5 ml) and DCM (1 ml). The precipitate formed was removed by suction-filtration and washed with a small amount of ether. The desired product 3-phenyl-1-oxa-2-azaspiro[4.5]dec-2-ene-8-carboxylic acid-3-fluoro-4-methanesulphonylaminobenzylamide was obtained as a trans isomer (138 mg, 19% of the theoretical amount).

Provenance & Evidence