Pyridine → (6R,7R)-7-[[(2Z)-2-(2-amino-1,3-thiazol-4-yl)-2-hydroxyiminoacetyl]amino]-8-oxo-3-(oxolan-2-yl)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

Methanesulphonyl chloride (96 μl, 1.25 mmol) was added to sodium 2-(2-tritylaminothiazol-4-yl)-2-(Z)-trityloxyiminoacetate (852 mg, 1.2 mmol) in DMF (2 ml) at <-40° C. The mixture was stirred 0.5 h at -30±10° C. then t-butyl (6R,7R)-7-amino-3-[(R)-tetrahydrofuran-2-yl]ceph-3-em-4-carboxylate (326 mg, 1 mmol) in DMF (2 ml), followed by pyridine (101 μl, 1.25 mmol), were added. The reaction was stirred for 1 h without further cooling then diluted with ethyl acetate, washed twice with water and with brine, dried, concentrated in vacuo and flash chromatographed eluting with 25, 30% ethyl acetate in hexane to give the title compound as a colourless foam (665 mg, 68%); νmax (CH2Cl2) 3395, 1787, 1722, 1687, 1527, 1449, 1156 and 1051 cm-1 ; δH (CDCl3 /CD3OH) 1.55 (9H, s), 1.65-2.25 (4H, m), 3.32 and 3.40 (2H, ABq, J 17.6 Hz), 3.8-4.0 (2H, m), 5.08 (1H, d, J 4.8 Hz), 5.13 (1H, dd, J 7.0, 8.1 Hz), 5.91 (1H, d, J 4.5 Hz), 6.56 (1H, s), 7.2-7.5 (30H, m). [Mass spectrum: +ve ion (3-nitrobenzyl alcohol, sodium acetate) MNa+ (1002)].

Provenance & Evidence