Chlorosulfonyl isocyanate → HCID 14326680, compound

Participants

Reaction Steps

To a suspension of 13.8 g of (S)-3-[[(phenylmethoxy)carbonyl]amino]-2-azetidinone in 500 ml of ethyl acetate was added 5.63 ml (0.0626 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., at which temperature a solution of silylated 1,4-dihydro-5-hydroxy-4-oxo-N-(2-oxo-1-imidazolidinyl)2-pyridinecarboxamide (prepared from a suspension of 14.9 g (0.0626 mol) of 1,4-dihydro-5-hydroxy-4-oxo-N-(2-oxo-1-imidazolidinyl)-2-pyridinecarboxamide in 500 ml of ethyl acetate by the addition of 46.4 ml of N-methyl-N-(trimethylsilyl)trifluoroacetamide (0.25 mol) and stirring for 30 minutes) was added slowly. Then 150 ml of dichloromethane was added, and the mixture was stirred at room temperature overnight. To the clear solution was added 26.2 ml of triethylamine (0.188 mol), followed by 300 g of ice and 200 ml of water. The pH was 6.5. After stirring for 11/2hours, the two phases were separated and the aqueous phase was washed with three 200 ml portions of ethyl acetate. After removal of residual ethyl acetate in vacuo, the pH of the aqueous phase was adjusted to 2 by the slow addition of 2N hydrochloric acid (47 ml) with cooling. The crystals were filtered off, suspended in 200 ml of ethyl acetate and stirred for one hour. Then the crystals were filtered off, washed twice with 30 ml of ethyl acetate and twice with 50 ml of petroleum ether and dried in vacuo, to yield 28.6 g of the title compound, melting point 190°-200° C., dec.

Provenance & Evidence