摘要:
Dihydrotriazinylthiomethyl-oxacephem compounds represented by the formula: ##STR1## wherein A is amino or substituted amino; COB is carboxy, protected-carboxy or a carboxy salt; E is hydrogen or methoxy; M is hydrogen or hydroxy-protecting group; and R is lower alkyl are useful as antibacterial agents.
摘要:
A process for preparing free carboxylic acids which comprises treating an optionally substituted benzyl ester with a Lewis acid, preferably in the presence of a cation acceptor, followed by hydrolysis, if required.
摘要:
Compounds represented by the following formula prepared from 6-aminopenicillanic acid are key intermediates in a stereo-specific synthesis of 1-oxadethiacephalosporins, highly active antibiotics: ##STR1## [wherein COA and COB each is carboxy or protected carboxy;Cox is carboxy, protected carboxy, or a group of the formula --COCQ.dbd.N.sub.2 or --COCHQ--Z (in which Q is hydrogen, lower alkyl or aryl; and Z is hydrogen or a nucleophilic group);Hal is halogen;R is lower alkyl or aralkyl; andY is hydrogen or acyl].
摘要:
An intermediate represented by following formula for synthesizing 3-hydroxy-3-cephem compounds. ##STR1## wherein A and B each is a hydrogen or amine substituent; R is a hydrogen or thiol substituent; Nal is a halogen; X is a hydroxy or carboxy protecting group; the broken line between A and R shows that when R and B are hydrogens, and A is a carboxylic acyl, the substituents can be combined to form an azetidimethiazoline bicyclic ring; and the enamine derivatives thereof.
摘要:
Azetidine derivatives of the formula: ##STR1## wherein A is amino or substituted amino; COB is carboxy or protected carboxy; R.sup.1 is .dbd.C(CH.sub.3).sub.2, ##STR2## (R.sup.4 is alkyl, aryl or aralkyl); OR.sup.2 and OR.sup.3 independently or taken together with each other represent a ketal; Y is hydrogen or methoxy; Z is hydrogen or halogen, and a process for preparation thereof. Used as intermediates in the preparation of potent antimicrobials 1-oxadethiacephalosporins.
摘要:
A novel chemical, fluorochlorocyclopropane (I) of the following formula: ##STR1## is prepared by the addition of fluorochlorocarbene to the corresponding olefin (II) of the following formula:CH.sub.2 .dbd.CR.sup.1 -R.sup.2The compound is a useful intermediate for synthesizing some chemicals, e.g., some cephalosporins.(wherein R.sup.1 is hydrogen, halogen, 1 to 8C alkylamino, alkoxy, or alkylthio andR.sup.2 is halogen, 1 to 8C alkylamino, alkoxy, or alkylthio).
摘要:
Compounds of the formula: ##STR1## (where COB is carboxy or protected carboxy and X is hydrogen or nucleophilic group)preparable by oxidation of the corresponding N-nitrosopenicillin derivatives are useful as starting materials for synthesizing known and useful cephalosporins.
摘要:
Antibacterial 7.alpha.-methoxy-3-cephem derivatives of the formula: ##STR1## [wherein R.sup.1 is hydrogen, or organic or inorganic acyl;R.sup.2 is alkyl; andCOR.sup.3 is carboxy or protected carboxy],methods of production, and pharmaceutical preparations thereof.
摘要:
Useful intermediates, 7.alpha.-acylamino-3-(oxo or exomethylene)-1-dethia-1-oxacepham-4.alpha.-carboxylates, are produced by the intramolecular carbenoid insertion of a 2-diazo-3-(oxo or exomethylene)-4-(3.alpha.-acylamino-2-oxoazetidin-4.beta.-yl)oxybutyrate prepared in several steps from the corresponding oxazolinoazetidinone and diketone.
摘要:
1-Oxa-cephalosporin analogues of the formula: ##STR1## [wherein X is 3-thienylmalonyl, phenylmalonyl, 4-hydroxyphenylmalonyl, or 2-fluoro-4-hydroxyphenylmalonyl;Y is hydrogen or methoxy; andR is hydrogen, alkali metal, or alkaline earth metal]and the preparation thereof.