Sumitomo Chemical Company, Limited

Toru Mitani

Takenari Nakagome

Hideo Agui

Mitsuo Nakashita

Toshiaki Komatsu

Yasuko Eda

Akio Izawa

Eiichi Murayama

Kousaku Okamura

Iwao Nakatsuka

Thiazolo[5,4-f]quinoline-8-carboxylic acid derivatives having either the general formula (I): ##STR1## wherein R.sub.1 is a lower alkyl group, a lower alkenyl group or a benzyl group; or the general formula (III-a): ##STR2## WHEREIN R.sub.3 is a lower alkyl group and X is a halogen atom; and methods for the preparation thereof. The compounds of the general formula (I) are useful as antibacterial agents against gram-negative and gram-positive bacteria. The compounds of the general formula (III-a) are useful as antifungal agents against eumycetes and also as an intermediate in a peparation of the compounds of the general formula (I).

Thiazolo(5,4-f)quinoline-8-carboxylic acid derivatives

Novel antibacterial agents consisting of a 2,3,5,8-tetrahydro-5-alkoxy-8-oxofuro(2,3-g)quinoline-7-carboxylic acid of the formula: ##STR1## wherein R is C.sub.1 -C.sub.4 alkyl, a process for producing the derivatives and pharmaceutical compositions containing the same. The above-identified derivatives possess antibacterial activity against gram-negative bacteria at test concentration levels of about 0.0001 to 1.0 mg/cc.

2,3,5,8-Tetrahydro-5-alkoxy-8-oxofuro(2,3-g)quinoline-7-carboxylic acid

A process for producing a compound of the formula: ##SPC1## Wherein Z is CH or N; R is a lower alkyl group, a lower alkenyl group, a cycloalkyl group or a hydroxyalkyl group; R.sub.1 is a hydrogen atom or lower alkyl group; when Z is N, R.sub.2, R.sub.3 and R.sub.4 are a hydrogen atom, a halogen atom a lower alkyl group, a lower alkoxyl group, a lower hydroxyalkyl group, a lower acyloxyalkyl group, trihalogenoalkyl group, a carboxyl group, a cyano group, or an aralkyl group; when Z is CH, R.sub.2, R.sub.3 and R.sub.4 are a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxyl group, a trihalogenoalkyl group, a cyano group, a nitro group, an alkylmercapto group, a lower alkylenedioxy group, or a lower alkylene bridge attached to the quinoline nucleus, which comprises heating a compound of the formula ##SPC2## Wherein R, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and Z are as defined above, followed, if desired, by hydrolyzing the product obtained, is disclosed. The product is useful as an antibacterial agent. An intermediate having the formula: ##SPC3## Wherein A is OR or a halogen atom, and R, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and Z are as defined above, and a process for its preparation are also disclosed.

Preparation of 1-(lower

Thiazolo[5,4-f]quinoline-8-carboxylic acid derivatives having either the general formula (I): ##SPC1## wherein R.sub.1 is a lower alkyl group, a lower alkenyl group or a benzyl group; or the general formula (III-a): ##SPC2## Wherein R.sub.3 is a lower alkyl group and X is a halogen atom; and methods for the preparation thereof. The compounds of the general formula (I) are useful as antibacterial agents against gram-negative and gram-positive bacteria. The compounds of the general formula (III-a) are useful as antifungal agents against eumycetes and also as an intermediate in a preparation of the compounds of the general formula (I).

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Kyoto, Japan

Toru Mitani