Methanesulfonyl chloride → benzhydryl (6R,7R)-7-[[(2Z)-2-methoxyimino-2-[2-(tritylamino)-1,3-thiazol-4-yl]acetyl]amino]-8-oxo-3-[(5-oxo-2H-furan-3-yl)methoxy]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

A stirred solution of 2-(2-tritylaminothiazol-4-yl)-2-(Z)-methoxyiminoacetic acid hydrochloride (300 mg) in dimethylformamide (4 ml) was cooled to -50° C. whilst under an inert atmosphere. N,N-Diisopropylethylamine (218 μl) was added followed by methanesulphonyl chloride (49 μl). The reaction was stirred for 30 min. at -50° C. before treating with pyridine (52 μl) followed by a solution of diphenylmethyl 7β-amino-3-(2,5-dihydro-2-oxofuran-4-ylmethyloxy)ceph-3-em-4-carboxylate (300 mg) in dimethylformamide (4 ml) and the temperature allowed to rise to 0° C. The reaction was stirred for 15 min. and then poured into ethyl acetate and water. The organic phase was washed with water (two times) and brine before drying over anhydrous magnesium sulphate. Chromatography on silica gel (Keiselgel) eluting with 4:1 ethyl acetate/hexane gave the title compound which was finally isolated as a foam (431 mg). υmax (CH2Cl2) 3400, 1785, 1755, and 1730cm-1 ; δH(CDCl3) 3.34 (2H, s), 4.08 (3H, s), 4.64 (2H, s) 4.73 (2H, bs), 5.11 (1H, d, J 4.5Hz), 5.79 (1H, dd, J 8.24Hz, 4.5Hz), 5.95 (1H, bs) 6.77 (1H, s), 6.90 (1H, s), 6.96 (1H, d, J 8.07Hz), 7.02 (1H, s), and 7.26-7.39 (25H, m). [Mass spectrum: FAB +ve ion (3NOBA/Na+)MH+ 904, MNa+ 926].

Provenance & Evidence