Trifluoroacetic acid → HCID 131717696, compound

Participants

Reaction Steps

To a suspension of 7β-[2-(2-aminothiazol-4-yl)-2-t-butoxycarbonylmethoxyiminoacetamido]-3-(4,5,6,7-tetrahydro-1-pyrazolo[1,5-a]pyrimidinio)methyl-3-cephem-4-carboxylate (syn isomer) (800 mg) in methylene chloride (2.4 ml) and anisole (0.8 ml) was added dropwise trifluoroacetic acid (1.6 ml) at 20° C. The stirring was continued for 3 hours at the room temperature. The reaction mixture was poured into ethyl acetate. The resulting precipitates were collected by filtration. The precipitates were dissolved in water (50 ml) and the mixture was adjusted to pH 6.5 with a saturated aqueous solution of sodium bicarbonate. The solution was subjected to column chromatography on HP-20 using water as an eluent and the object fractions were adjusted to pH 2.0 with 1N hydrochloric acid. The resulting solution was subjected to column chromatography on HP-20 using 15% aqueous isopropyl alcohol as an eluent and the object fractions were lyophilized to give 7β-[2-(2-aminothiazol-4-yl)-2-carboxymethoxyiminoacetamido]- 3-(4,5,6,7-tetrahydro-1-pyrazolo[1,5-a]pyrimidinio)methyl-3-cephem-4-carboxylate (syn isomer) (300 mg).

Provenance & Evidence