Process for preparing 7-aminocephalosporins
AssigneeTakeda Chemical Industries, Ltd.
InventorsSusumu Tsushima, Norichika Matsumoto, Masayasu Kato
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Abstract
7-Aminocephalosporin of the formula: ##STR1## wherein R.sup.2 is 3-oxobutyryloxy group, 1-methyl-1H-tetrazol-5-ylthio group or 1-(2-dimethylaminoethyl)-1H-tetrazol-5-ylthio group, or its salt is prepared by first protecting the carboxyl group at 4-position of the compound of the formula: ##STR2## wherein R.sup.1 is an amino group which may be protected and R.sup.2 is the same as defined above, or its salt with an acetyl or propionyl halide, then cleaving the amide group at 7-position of said compound by converting the amide bond to an imino halide, then to an imino ether and subjecting the imino ether to solvolysis.
Claims11
A process for preparing a compound of the formula:
- ##STR5## wherein R.sup.2 is 3-oxobutyryloxy group, 1-methyl-1H-tetrazol-5-ylthio group or 1-(2-dimethylaminoethyl)-1H-tetrazol-5-ylthio group, or its salt which comprises reacting a compound of the formula:
- ##STR6## wherein R.sup.1 is an amino group which may be protected and R.sup.2 is the same as defined above or its salt with an acetyl or propionyl halide at -10.degree. C. to -50.degree. C., then with an imino halide-forming agent to be converted to an imino halide, which is further reacted with a lower alkanol to be converted to an imino ether, and subjecting the imino ether to solvolysis.
Dependencies are inferred from the claim text.