O1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]1([NH:9][C:10](=[O:16])[O:11][C:12]([CH3:15])([CH3:14])[CH3:13])[CH2:8][CH2:7]1.[N:17]#[N:18].C([O-])(O)=O.[Na+].BrN1C(=O)CCC1=O>CC(C)=O.O.C1COCC1>[N:17]1[CH:5]=[CH:4][CH:3]=[C:2]([C:6]2([NH:9][C:10](=[O:16])[O:11][C:12]([CH3:15])([CH3:14])[CH3:13])[CH2:8][CH2:7]2)[N:18]=1A solution of tert-butyl 1-(furan-2-yl)cyclopropylcarbamate (2.15 g, 9.64 mmol, 1.0 eq) in acetone (86 ml) and water (86 ml) was purged N2 and cooled to −20° C. NaHCO3 (1.62 g, 19.28 mmol, 2.0 eq) and N-bromosuccinimide (2.23 g, 12.52 mmol, 1.3 eq) were added to the mixture at −20° C. which was stirred at the same temperature for 2 hr. To the reaction mixture at −20° C. was added THF (4.3 ml) and the temperature raised to 0° C. over 30 min. Acetone was removed from the reaction mixture by a stream of N2 and to the residue at 0° C. was added isopropanol (86 ml) followed by hydrazine hydrate (12.9 ml). The reaction mixture was stirred at r.t. overnight. Product formation was confirmed by LCMS. After removal of the solvent by vacuum, the residue was diluted with water and extracted with EtOAc. The organic was washed with brine, dried over Na2SO4, filtered and concentrated. The crude product was purified by silica gel (60-120) column chromatography using 4% MeOH/CHCl3 as eluent. Yield: 0.8 g (36%). 1H NMR (400 MHz, CDCl3): δ 8.95 (d, J=3.6 Hz, 1H), 7.53 (d, J=8 Hz, 1H), 7.39 (m, 1H), 5.45 (bs, 1H), 1.82 (m, 2H), 1.46 (s, 9H) 1.24 (m, 2H). LCMS: (ES+) m/z=236.2 (M+H)+
Loading…
