Trifluoroacetic acid → (6R)-trans-3-chloromethyl-7-[(2,5-dichlorophenyl)thioacetamido]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A slurry of (6R)-trans-3-chloromethyl-7-[(2,5-dichlorophenyl)thioacetamido]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate, diphenylmethyl ester (10.0 g, 15.8 mmol) in CH2Cl2 (200 mL) at 0° C. was treated with anisole (24 mL) and then trifluoroacetic acid (80 mL). The resulting solution was stirred for 1 h at 0° C. and then concentrated under reduced pressure. The residue was stirred with Et2O, and the resulting solid was collected by filtration to give 5.20 g of (6R)-trans-3-chloromethyl-7-[(2,5-dichlorophenyl)thioacetamido]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid as a white solid (70% yield), m.p. 125° C. 1H NMR (300 MHz, DMSO-d6) δ3.51 (d, J=18 Hz, 1H), 3.70 (d, J=18 Hz, 1H), 3.91 (s, 2H), 4.52 (d, J=11 Hz, 1H), 4.58 (d, J=11 Hz, 1H), 5.13 (d, J=5 Hz, 1H), 5.70 (dd, J=5, 8 Hz, 1H), 7.24 (dd, J=2, 8 Hz, 1H), 7.47 (dd, J=2, 8 Hz, 1H), 9.28 (d, J=8 Hz, 1H).

Provenance & Evidence