| 摘要 |
<p>1,244,679. Isoxazolyl penicillins. TOYO JOZO K.K. 28 Aug., 1969 [28 Aug., 1968; 12 April,. 1969; 31 May, 1969; 28 June, 1969], No. 42890/69. Heading C2A. Isoxazolyl penicillins of the general formula wherein R represents H or a C 1 -C 4 alkyl radical, and R 1 and R 2 , which may be the same or different, are H or halogen atoms, and the non-toxic salts of the compounds in which R is H, are prepared by reacting a penicillin G ester of the general formula in which R<SP>1</SP> is a protective group for the carboxyl group which is either an alkyl radical R or a group which can be easily eliminated without having a detrimental effect on the structure of the penicillin, with a chlorinating agent in the presence of a tertiary organic amine to give a compound of the general formula which is reacted with an isoxazolyl carboxylate of formula in which M represents a metal atom, to give a diacyl penicillin ester of general formula which is then subjected to dephenylacetylation, whereafter, when R<SP>1</SP> is a group capable of being easily eliminated without having a detrimental effect on the structure of the penicillin, the resulting product is so treated in order to eliminate the protective group from the carboxyl group, and the free acid thus obtained is, if desired, neutralized with a non-toxic inorganic or organic base.</p> |
