7β-[(Z)-2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[3-amino-4-aminomethyl-2-(2-hydroxyethyl)-1-pyrazolio]methyl-3-cephem-4-carboxylate (5.0 g) was dissolved in water (100 ml), and 2.0 M sulfuric acid (4.0 ml) was added to the solution. The mixture was freeze-dried to give crude 7β-[(Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[3-amino-4-aminomethyl-2-(2-hydroxyethyl)-1-pyrazolio]methyl-3-cephem-4-carboxylate hydrogensulfate (5.18 g) as an amorphous solid. The amorphous solid (1.0 g) was dissolved in water (1.0 ml). To the solution was added acetonitrile (5.0 ml) dropwise. After stirring at room temperature for 2 hours, white crystals precipitated. The precipitated crystals were collected by filtration on a glass filter, washed with a small amount of water/acetonitrile (1:5) and dried under reduced pressure to give 7β-[(Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[3-amino-4-aminomethyl-2-(2-hydroxyethyl)-1-pyrazolio]methyl-3-cephem-4-carboxylate hydrogensulfate (880 mg) as white crystals. 1H-NMR(D2O) δ1.61(6H, s), 3.20 and 3.53 (2H, ABq, J=18.0 Hz), 3.87 (2H, t, J=4.6 Hz), 4.09 (2H, s), 4.38 (2H, t, J=4.6 Hz), 5.16 (2H, s), 5.28 (1H, d, J=4.8 Hz), 5.88 (1H, d, J=4.8 Hz), 8.10 (1H, s)
