N-bromobutanimide → HCID 9957458, compound

Participants

Reaction Steps

3,3-dibromo-alpha-(1-methylethylidene)-2-[(5-methyl-isoxazole-3-yl)-aminosulfinyl]-4-oxo-1-azetidine acetic acid benzyl ester (5.61 g; 0.01 mole) was dissolved in chloroform (120 mL), N-bromosuccinimide (7.12 g; 0.04 mole) was added to the reaction mixture and it was stirred for two hours at room temperature. The reaction mixture was evaporated, methylene chloride and n-hexane were added to the dry residue, the precipitate was sucked off and the filtrate was evaporated to a dry residue. The obtained product was purified by flash chromatography with the solvent system petroleum ether-methylene chloride (1:1). There was obtained 2,3,3-tribromo-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid benzyl ester (3.05 g, 61.5%), which was subjected to a reaction with silver tetrafluoroborate in methanol analogously to the reaction described under 1a. After isolation 3,3-dibromo-2-methoxy-alpha-(1-methylethylidene)-4-oxo-1-azetidine acetic acid benzyl ester with spectroscopic data identical to those disclosed under 1a was obtained.

Provenance & Evidence