Chlorosulfonyl isocyanate → HCID 14326680, compound

Participants

Reaction Steps

To a suspension of 1.76 g (0.008 mol) of (S)-(2-oxo-3-azetidinyl)carbamic acid, phenylmethyl ester in 80 ml of ethyl acetate was added 0.7 ml (0.008 mol) of chlorosulfonyl isocyanate at room temperature for 1 hour to yield a solution of (S)-[1-[[(chlorosulfonyl)amino]carbonyl]-2-oxo-3-azetidinyl]carbamic acid, phenylmethyl ester. The solution was cooled to 0° C. and a solution of silylated 2-amino-4,5-dihydroxybenzoic acid, prepared from 1.35 g (0.008 mol of 2-amino-4,5-dihydroxybenzoic acid in 80 ml of ethyl acetate by the addition of 4.45 ml (0.024 mol) of N-methyl-N-(trimethylsilyl)trifluoroacetamide and warming to 50° C. for 60 minutes, was added dropwise. The reaction mixture was stirred overnight at room temperature. Then ice water (~200 ml) was added and stirring was continued for an additional 30 minutes. The two phases were separated, the aqueous phase was layered with ethyl acetate and acidified to pH 2 (2N hydrochloric acid). The organic phase was dried and evaporated. On treatment with ether, 2.4 g of a solid residue was obtained.

Provenance & Evidence