Phosgene → HCID 68128259, compound

Participants

Reaction Conditions

Reaction Steps

To a cold solution (0° C) of 7-amino-3-(2-methyl-1,3,4-thiadiazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid (6.888 g) in 80 ml. of methylene chloride is added trichlorsilane. The medium is stirred for 15 minutes at 20° C and 100 ml. of toluene is added. The solution is cooled up to -60° C and triethylamine (28 ml) and liquid (-70° C) phosgene (3.2 ml) are added. The medium is stirred for 3 hrs at -50° C. Most of the solvents is then eliminated under reduced pressure (1 mm Hg), the residual solution is allowed to reach room temperature and then immediately added to allylamine (0.888 ml) in methylene chloride (20 ml) with stirring for 10 hrs. After hydrolysis of the trimethylsilylester with water, the solvent is removed by evaporation and the residue is purified by chromatography on Silicagel Merck 0.2-0.06 mm to yield 7 -(3-allylureido)- 3-(2-methyl-1,3,4-thiadiazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid with the same characteristics as the product obtained in Example 15.

Provenance & Evidence