Chlorosulfonyl isocyanate → HCID 14326680, compound

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Reaction Steps

To a suspension of 6.61 g (0.030 mol) of (S)-(2-oxo-3-azetidinyl)carbamic acid, phenylmethyl ester in 240 ml of dry ethyl acetate, 2.62 ml (0.030 mol) of chlorosulfonyl isocyanate was added and the mixture was stirred for 1 hour at room temperature to form a solution of (S)-[1-[[(chlorosulfonyl)amino]carbonyl]-2-oxo-3-azetidinyl]carbamic acid, phenylmethyl ester. After cooling to 0° C., a solution of 12.54 ml (0.090 mol) of triethylamine in 60 ml of dry dichloromethane was dropped in, followed by the dropwise addition of the freshly prepared solution A (0° C.). Overnight the mixture was stirred well at room temperature, then poured into ice water and acidified to pH 2 by the addition of 1N hydrochloric acid. The two phases was separated and the aqueous phase was extracted twice with ethyl acetate. 200 ml of ice water were added to the combined organic phases and the pH of the mixture was adjusted to pH 6.5 by the addition of 1N sodium hydroxide. The aqueous phase was separated, washed again with ethyl acetate, concentrated in vacuo and finally freeze dried; yield: 13.11 g.

Provenance & Evidence