反应详情

The solution of 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-(1-methyl-1-piperazinio)methyl-3-cephem-4-carboxylate (syn isomer) (540 mg) in acetone (5 ml) and water (5 ml) was adjusted to pH 7.0 with a saturated aqueous solution of sodium bicarbonate. To the mixture was added 3,4-diacetoxybenzoyl chloride (308 mg) at pH 6.5-7.0. The mixture was stirred for an hour and evaporated in vacuo to remove acetone. The residue was adjusted to pH 8.5 with a saturated aqueous solution of sodium bicarbonate and then stirred for 2 hours at room temperature. The mixture was adjusted to pH 3.5 with 3N hydrochloric acid and then filtered. The filtrate was subjected to column chromatography on Diaion HP-20 using 5% aqueous isopropyl alcohol as an eluent. The eluate was evaporated in vacuo to remove isopropyl alcohol and then lyophilized to give 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-[1-methyl- 4-(3,4 -dihydroxybenzoyl)-1-piperazinio]methyl-3-cephem-4-carboxylate (syn isomer) (265 mg).

1. customevaporated in vacuo
2. customto remove acetone
3. stirringstirred for 2 hours at room temperature
4. filtrationfiltered
5. customThe eluate was evaporated in vacuo
6. customto remove isopropyl alcohol