Methanesulfonyl chloride → (4-methoxyphenyl)methyl (6R,7R)-7-[[(2Z)-2-methoxyimino-2-[2-(tritylamino)-3H-thiadiazol-4-yl]acetyl]amino]-8-oxo-3-[(2S)-oxolan-2-yl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

Mesyl chloride (65μl) was added to 2-(Z)-methoxyimino-2-(2-tritylaminothiadiazol-4-yl)acetic acid (370mg) and N,N-diisopropylethylamine (146μl) in dichloromethane (5ml) at -20° C. The reaction mixture was stirred at -20° C. for 1 hour then added to an ice cold solution of 4-methoxybenzyl (6R,7R)-7-amino-3-[(S)-tetrahydrofuran-2-yl]ceph-3-em-4-carboxylate (335mg) and pyridine (70μl) in dichloromethane (5ml). The reaction was stirred for 1 hour, concentrated and flash chromatographed on silica gel eluting with 30,50,60 and 70% ethyl acetate in hexane to afford the title compound as a foam (300mg); vmax (CHCl3) 3398, 1784, 1724, 1691, 1516, 1134 and 1107 cm-1 ; δH (CDCl3, 250MHz) 1.55-1.75 (1H,m), 1.80-2.05 (2H,m), 2.25-2.45 (1H,m), 3.30 and 3.61 (2H, ABq, J 18.3Hz), 3.75-4.00 (2H,m), 3.81 (3H,m), 4.16 (3H,m), 4.85-5.00 (1H,m), 5.00 (1H,d, J 4.8Hz), 5.17 (2H,s), 5.92 (1H,dd, J 4.8Hz), 6.72 (1H,d,J 7.8Hz) and 6.88 and 7.30 (19H,m). [Mass spectrum: +ve ion (3-nitrobenzyl alcohol, sodium acetate) MNa+ (839)].

Provenance & Evidence