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

Participants

Reaction Steps

2-(Z)-Methoxyimino-2-(2-tritylaminothiazol-4-yl)acetic acid hydrochloride (0.751 g) in DMF (5 ml) was treated with methanesulphonyl chloride (0.179 g, 0.121 ml) and diisopropylethylamine (0.404 g, 0.544 ml) as described in Example 1(g). This was then treated with t-butyl (6R,7R)-7-amino-3-[(RS)-tetrahydrofuran-3-yl]ceph-3-em-4-carboxylate (0.464 g) and pyridine (0.112 g, 0.114 ml) in DMF (5 ml). Following work up and purification by flash chromatography with 40, 50 and 60% ethyl acetate/hexane, the title compound was obtained as a yellow foam (0.874 g, 82%); νmax (CH2Cl2) 3398, 1783, 1731 (shoulder), 1718 and 1688 cm-1 ; δH (CDCl3) 1.53 (9H, s), 1.69-2.43 (3H, m's), 3.29 and 3.46 with 3.34 and 3.48 (2H, 2ABq's, J 17.7 and 17.7 Hz), 3.63-4.07 (6H, m's and s), 5.03 and 5.06 (1H, 2d's, J 4.8 and 4.8 Hz), 5.84-5.90 (1H, m), 6.73 and 6.74 (1H, 2s), 6.76 and 6.90 (1H, 2d's, J 8.7 and 8.7 Hz exchangeable with D2O), 7.02 (1H, br. s, exchangeable with D2O) and 7.31 (15H, s). [Mass spectrum: +ve ion (3NOBA, Na+) MNa+ (774)].

Provenance & Evidence