Penicillin G → 4-methoxybenzyl (2RS)-2-hydroxy-2-[(3R,4R)-4-mercapto-3-phenylacetamidoazetidin-2-on-1-yl]acetate

Participants

Reaction Steps

Toluene-4-sulphonic acid (6.0 g, 31.5 mmol) in water (15 ml) was added to a solution of 4-methoxybenzyl (2RS)-2-hydroxy-2-[(1R,5R)-3-benzyl-4-thia-2,6-diazabicyclo [3.2.0]hept-2-en-7-on-6-yl]acetate (7.42 g, 18.0 mmol) prepared from Penicillin G as described for the benzhydryl ester derived from Penicillin V, S. Yamamoto, N. Haga, T. Aoki, S. Hayashi, H. Tanida, and W. Nagata, Heterocycles, 1977, 8, 283) in dichloromethane (30 ml) and acetone (30 ml). After stirring for 2.5 h at room temperature, the reaction mixture was diluted with dichloromethane, washed with water (×2), dried and concentrated in vacuo to yield crude 4-methoxybenzyl (2RS)-2-hydroxy-2-[(3R,4R)-4-mercapto-3-phenylacetamidoazetidin-2-on-1-yl]acetate as a yellow foam.

Provenance & Evidence