Chlorosulfonyl isocyanate → HCID 70581038, compound

Participants

Reaction Steps

3-Hydroxymethyl-7-(p-nitrobenzyloxycarbonylamino) 3-cephem-4-carboxylic acid (2.0 g.; 5 m. mole) was suspended in dry acetonitrile (100 ml) and with stirring was cooled to 0°-5° C. under nitrogen. Chlorosulphonylisocyanate (1.1 ml.; 12.5 m. mole) was added dripwise under nitrogen giving a clear solution almost immediately after the addition. The solution was stirred for 1 hour at 0°-5° C. and evaporated to dryness. The resulting gum was dissolved in aqueous sodium bicarbonate such that the final solution was at pH 1.5. This aqueous solution (150 ml) was layered with ethyl acetate (200 ml) and the mixture was stirred at 20° C. for 18 hours. The ethyl acetate layer was separated, washed with brine, dried over magnesium sulphate and evaporated to dryness to give 3-carbamoyloxymethyl-7-(p-nitrobenzyloxycarbonylamino)-3-cephem-4-carboxylic acid as a cream powder (1.73 g.; 77% of theory). Thin layer chromatography in chloroform, acetone, acetic acid (50:50:7) revealed a single spot at Rf =0.11. δ (DMSO) 8.64 (1H, d, CONH), AA'BB' 8.3 and ##STR13## 6.54 (2H, S, --CONH2 exchanges D2O), 5.55 (2H, m, H7 and α-protons), 5.28 (2H, s, benzylic CH2), 5.12 (1H, d, H6), AB quartet 4.9 and 4.6 (2H, 3-CH2), and 3.55 (2H, s, S-CH2 --), γ max (nujol) 1780 (β-lactam C=O) 1710 (broad), 1520 (NO2)cm-1 ; λ max (EtOH) 266 nm (εm 16220).

Provenance & Evidence