反应详情

To a suspension of 7β-[2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetamido]-3-[1-methyl-4-(3,4-dihydroxybenzoyl)-1-piperazinio]methyl-3-cephem-4-carboxylate (syn isomer) (1.52 g) in methanol (9 ml) was added concentrated hydrochloric acid (1.92 ml). After being stirred at room temperature for 4 hours, the solution was poured into ice water (40 ml) and adjusted to pH 2 with a saturated aqueous solution of sodium bicarbonate. The mixture was concentrated in vacuo to remove methanol. The concentrate was adjusted to pH 2 with a saturated aqueous solution of sodium bicarbonate and subjected to column chromatography on "Diaion HP-20" (40 ml), and the elution was carried out with 40% aqueous isopropyl alcohol. The eluate was concentrated in vacuo and lyophilized to give 7β-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-[1-methyl-4-(3,4-dihydroxybenzoyl)-1-piperazinio]methyl-3-cephem-4-carboxylate (syn isomer) (548 mg).

1. concentrationThe mixture was concentrated in vacuo
2. customto remove methanol
3. wash" (40 ml), and the elution
4. concentrationThe eluate was concentrated in vacuo