Reaktion #691109

Reaktionsgleichung

tert-butyl (4-{(2R,3R)-1-(4-fluorophenyl)-3-[(3-nitropyridin-2-yl)dithio]-4-oxoazetidin-2-yl}phenoxy)acetate

triphenylphosphine

triethylamine

2-bromo-1-(2,3-dihydro-1,4-benzodioxin-6-yl)ethanone

→

desired compound

{4-[(2R,3R)-3-{[2-(2,3-dihydro-1,4-benzodioxin-6-yl)-2-oxoethyl]thio}-1-(4-fluorophenyl)-4-oxoazetidin-2-yl]phenoxy}acetic Acid

Lösungsmittel

acetone

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenthe mixture was concentrated
2. 2
   workup.ADDITIONTo the residue was added dichloromethane (3 ml)
3. 3
   workup.WAITAfter 30 minutes
4. 4
   EinengenThe mixture was concentrated and to the residue
5. 5
   workup.ADDITIONwas added formic acid (2 g) and trifluoroacetic acid (0.2 g)
6. 6
   SonstigeThe crude product obtained
7. 7
   Sonstigewas purified through preparative HPLC
8. 8
   SonstigeFreeze drying of pure fractions

Vorschrift

To a solution of tert-butyl (4-{(2R,3R)-1-(4-fluorophenyl)-3-[(3-nitropyridin-2-yl)dithio]-4-oxoazetidin-2-yl}phenoxy)acetate (0.100 g, 0.179 mmol) in acetone (2 ml) and water (0.5 ml) was added triphenylphosphine (0.047 g, 0.179 mmol). After 30 minutes, the mixture was concentrated. To the residue was added dichloromethane (3 ml) followed by the addition of triethylamine (0.073 g, 0.717 mmol) and 2-bromo-1-(2,3-dihydro-1,4-benzodioxin-6-yl)ethanone (0.115 g, 0.448 mmol). After 30 minutes, full conversion of the thiol had been achieved. The mixture was concentrated and to the residue was added formic acid (2 g) and trifluoroacetic acid (0.2 g). The mixture was allowed to stir at room temperature for 3 h. The crude product obtained was purified through preparative HPLC using an eluent of 10-50% CH3CN in 0.1M NH4OAc buffer. Freeze drying of pure fractions afforded the desired compound. 1H NMR [(CD3)2SO), 400 MHz] δ 4.21-4.32 (m, 9H), 5.09 (d, 1H), 6.78-7.44 (m, 11H).

Quelle