HCID 13180422, compound → HCID 178494432, compound

Participants

Reaction Steps

Silver tetrafluoroborate (100 mg, 0.5 mmole) was added to a mixture of diphenylmethyl 7-[(Z)-2-(2-t-butoxycarbonylprop-2-oxyimino)-2-(2-tritylaminothiazol-4-yl)acetamido]-3-iodomethyl-3-cephem-4-carboxylate (VII-4') (577 mg, 0.5 mmole) and 5-methoxy-4-methylthiazole (146 mg, 1 mmole) [prepared according to the procedure described by D. S. Tarbell et al., J. Am. Chem. Soc., 72, 3138 (1950)] in methylene chloride (50 ml). The mixture was stirred for 20 minutes at room temperature and filtered. The filtrate was washed with water, evaporated under reduced pressure and the residue was triturated with ether to give the quaternized salt, which was collected by filtration (yield, 475 mg). The quaternized product was dissolved in cold TFA (2 ml), stirred for 1 hour at room temperature and evaporated under reduced pressure below 30° C., and the residue was triturated with ether. The crude TFA salt was collected by filtration (yield, 281 mg) and purified by HPLC (Column: Lichrosorb RP-18, Solvent: 0.01M NH4H2PO4 (pH 7):CH3OH=85:15). The fractions containing the desired compound were combined and concentrated under reduced pressure below 30° C. The concentrate was acidified to pH 2 (dilute HCl), chromatographed on a column of HP-20 (1.3×10 cm) and eluted with water and then with water-methanol (1:1). The fractions containing the desired product were combined, evaporated under reduced pressure and freeze-dried to give the title compound [Ii] as an amorphous powder. Yield, 61 mg (20%).

Provenance & Evidence