| 摘要 |
1372570 Penicillin esters BRISTOL-MYERS CO 26 Nov 1971 [27 Nov 1970] 55105/71 Heading C2A Novel penicillin esters having the Formula (I) wherein X is hydrogen or a cation, are prepared by either (a) reacting a compound of formula wherein Y and R are each a cation, with a halomethyl pivalate of formula wherein R<SP>2</SP> is Cl, Br or I, or its chemical equivalent as an esterifying agent; or (b) reacting a compound of formula with trimethylamine-sulphur trioxide, Reaction (a) is preferably performed in hexamethlphosphortriamide using equimolar quantities of the reactants. Reaction (b) may be carried out in dry methylene chloride using a 10% molar excess of the trimethylamine-sulphur trioxide. The compounds may be converted to their base salts by treatment with a basic compound of the inorganic cation (e.g. Na, Ca, K) Al or NH 4 ) or with an organic base. When such treatment is conducted in aqeous solution, the salt is obtained as the mono- or di-hydrate. Pharmaceutical compositions having antibiotic activity against gram-positive and gramnegative bacteria comprise a penicillin ester of Formula (I) together with a physiologically acceptable diluent or carrier. |
