Chlorosulfonyl isocyanate → HCID 14326680, compound

Participants

Reaction Steps

To a suspension of 5.19 g (0.0236 mol) of (S)-3-[[(phenylmethoxy)carbonyl]amino]-2-azetidinone in 160 ml of ethyl acetate was added with stirring at room temperature 2.05 g (0.0236 mol) of chlorosulfonyl isocyanate. The mixture was stirred for 1 hour at room temperature to form a solution of (S)-1-[[(chlorosulfonyl)amino]carbonyl]-3-[[(phenylmethoxy)carbonyl]amino]-2-azetidinone. The solution was cooled to 0° C., 80 ml of dichloromethane was added followed by 9.9 ml (0.0707 mol) of triethylamine and a solution of silylated 1,4-dihydro-5-hydroxy-4-oxo-2-pyridinecarboxylic acid, hydrazide (obtained from a suspension of 3.99 g (0.0236 mol) of 1,4-dihydro-5-hydroxy-4-oxo-2-pyridinecarboxylic acid, hydrazide in 50 ml of ethyl acetate and 8.75 ml of N-methyl-N-(trimethylsilyl)trifluoroacetamide (8.75 ml=0.0472 mol)). The mixture was stirred at room temperature overnight, then ice water was added and stirring was continued for an additional 30 minutes. The aqueous phase was layered with ethyl acetate and acidified to pH 2.5. The precipitate crystallized after stirring for one hour, yielding 6.6 g of the title compound.

Provenance & Evidence