Phenylenediamines and process for preparing the same

Details Phenylenediamines and process for preparing the same Phenylenediamines and process for preparing the same

1998-10-15

1999-11-30

Geist, Gary

Organic compounds -- part of the class 532-570 series

Organic compounds

Carboxylic acid esters

C07C26100

Patent

active

059945753

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD

The present invention relates to phenylenediamines useful as intermediates for synthesis of pyridonecarboxylic acid derivatives or salts thereof which have excellent antibacterial action and can be absorbed well when administered perorally, and to a process for preparing the same.


BACKGROUND ART

Among compounds having a basic skeleton of pyridonecarboxylic acid there have been known a variety of compounds useful as synthetic antibacterial agents, since they have excellent antibacterial activity and a wide antibacterial spectrum. Of these, in the clinical field, as therapeutic agents for infectious diseases there have been widely used compounds such as norfloxacin (Japanese Patent Application Laid-Open (kokai) No. 53-141286), enoxacin (Japanese Patent Application Laid-Open (kokai) No. 55-31042), ofloxacin (Japanese Patent Application Laid-Open (kokai) No. 57-46986), ciprofloxacin (Japanese Patent Application Laid-Open (kokai) No. 58-76667), and tosufluoxacin (Japanese Patent Application Laid-Open (kokai) No. 60-228479).
However, these compounds are not perfectly satisfactory in terms of antibacterial activity, intestinal absorption efficiency, stability in metabolism, and side effects, inter alia, phototoxicity and cytotoxicity.
In view of the foregoing, an object of the present invention is to provide pyridonecarboxylic acid-based antibacterial agents which have satisfactory antibacterial activity, intestinal absorption efficiency, stability in metabolism, and acceptable side effects particularly in terms of phototoxicity and cytotoxicity; and to provide intermediates for synthesis thereof.


DISCLOSURE OF THE INVENTION

The present inventors have conducted earnest studies in an attempt to obtain a compound which may serve as a clinically excellent synthetic antibacterial agent, and have found that pyridonecarboxilic acids represented by the below-described formula (A) have excellent antibacterial activity to Gram-negative and -positive bacteria and remarkably low toxicity and are therefore suitable as synthetic antibacterial agents, and that the compounds (A) can be advantageously produced on an industrial scale through a method in which reaction proceeds according to the below-described reaction scheme via phenylenediamines represented by formula (1), leading to completion of the present invention. ##STR2## [wherein R.sup.1 represents a lower alkyl group; R.sup.2 represents a hydrogen atom, a halogen atom, a hydroxy group, a lower alkyl group, or an amino group; R.sup.3 represents a hydrogen atom or a halogen atom; X.sup.1 represents a hydrogen atom or a halogen atom; X.sup.2 represents a halogen atom; Z represents a halogen atom or a saturated cyclic amino group which may have substituents; A represents a nitrogen atom or --CY=(Y represents a hydrogen atom, a halogen atom, a lower alkyl group, or a lower alkoxy group); R represents an alkyl group or an aralkyl group which may have a substituent; R.sup.4 represents a lower alkoxy group or a group of --N(R.sup.5)R.sup.6 (each of R.sup.5 and R.sup.6 represents a lower alkyl group); and L represents a halogen atom].
Briefly, an acrylate ester (C) and a phenylenediamine (1) are condensed and cyclized together to form a compound (B), from which the amino-protective group ( --COOR) is then removed, to thereby obtain a compound (A).
The phenylenediamine compounds (1) used in the reaction are novel compounds; thus they are important intermediates for synthesis in the reaction.
Accordingly, the present invention provides phenylenediamines represented by the above-described formula (1), salts thereof, and a process for preparing the same.


MODES FOR CARRYING OUT THE INVENTION

In the above-described formula (1), alkyl groups represented by R preferably have 1 to 18 carbon atoms. Specifically, mention may be given of a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, linear or branched pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl,

REFERENCES:
Database CAPLUS on STN, Acc. No. 1995:621678. IWAZAWA et al., `Preparation of uracil derivative by cyclocondensation of alkyl 4,4,4-trifluoro-3-methylaminocrotonate with alkyl phenylcarbamate.` JP 07061975 A2 (abstract), 1995.

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