Phosphorus oxychloride → 7-{2-[2-Amino-1,3-thiazol-4-yl]-2-[3-(3,4-diacetoxybenzoyl)carbazoyl]methoxyiminoacetamido}-3-[(5-methyl-1,3,4-thiadiazol-2-yl)thiomethyl]-3-cephem-4-carboxylic acid 1-ethoxycarbonyloxyethyl ester

Participants

Reaction Steps

In 40 ml of DMF was dissolved 6.309 g (9.5 mmole) of 7-[2-(2-formylamino-1,3-thiazol-4-yl)-2-(3-formylcarbazoyl)methoxyiminoacetoamido]-3-[(5-methyl-1,3,4-thiadiazol-2-yl)thiomethyl]-3-cephem-4-carboxylic acid sodium salt and the mixture was ice-cooled, and 4.88 g (20 mmole) of 1-iododiethylcarbonate was added thereto and stirred at room temperature for 3 hours. To the resulting mixture was added 700 ml of ethyl acetate and the mixture was washed with water and then washed with a saturated saline solution, dried over anhydrous magnesium sulfate and the solvent was distilled out. The residue was purified through silica gel column chromatography (eluent: 5% to 10% methanol-chloroform). To 30 ml of ice-cooled methanol was added 0.92 g (6 mmole) of phosphorus oxychloride and then purified product through column, and the mixture was stirred for 1.5 hours under ice-cooling. The resulting mixture was added dropwise into 800 ml of ether while vigorously stirring and resulting precipitates were collected by filtration and dried. After the resulting product was dissolved in 30 ml of methylene chloride and ice-cooled, 25 ml (10 mmole) of N,O-bis(trimethylsilyl)acetamide was added thereto and the mixture was stirred for 10 minutes. Then, 0.9 g (3.5 mmole) of 3,4-diacetoxybenzoic acid chloride was added thereto and the mixture was stirred for one hour under ice-cooling. The resulting mixture was added dropwise into 800 ml of ether and resulting precipitates were collected by filtration, washed with ether and then dried to obtain 3.07 g of the title compound. (Yield: 35.5%)

Provenance & Evidence