Pyridine → tert-butyl (6R,7R)-7-[[(2Z)-2-methoxyimino-2-[2-(tritylamino)-1,3-thiazol-4-yl]acetyl]amino]-8-oxo-3-[(2S)-5-oxooxolan-2-yl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

Methanesulphonyl chloride (23 μl, 0.3 mmol) was added to sodium 2-(Z)-methoxyimino-2-(2-tritylaminothiazol-4-yl)acetate (0.12 g,0.25 mmol) in DMF (0.5 ml) at -40° C. The mixture was allowed to warm to -10° C. over 0.5 h then cooled to -30° C. and t-butyl (6R,7R)-7-amino-3-[(5S)-2-oxotetrahydrofuran-5-yl]ceph-3-em-4-carboxylate (68 mg, 0.2 mmol) in DMF (1 ml) and pyridine (24 μl, 0.3 mmol) was added. The reaction was stirred for 1 h without cooling, then diluted with ethyl acetate, washed twice with water and brine, dried, concentrated and flash chromatographed, eluting with 40,50% ethyl acetate in hexane, to give the title compound (92 mg,60%), δH (CDCl3) 1.53 (9H,m), 1.9-2.1 (1H,m), 2.5-2.8 3H,m), 3.27 and 3.57 (2H,ABq,J18.7 Hz), 4.07 (3H,s), 5.06 (1H,d,J5Hz), 5.6-5.8 (1H,m), 5.98 (1H,dd,J5,9 Hz), 6.72 (1H,d,J9 Hz), 6.74 (1H,s), 7.02 (1H,s), 7.2-7.4 (15H,m); [mass spectrum: +ve ion (thioglycerol)MH+, 766].

Provenance & Evidence