Certain substituted 6,7-dihydro-1-oxo-1H,5H-benzo[ij]-quinolizine-2-carboxylic acids and hydrazides, esters, amides and salts thereof, intermediates therefor, and a process for their preparation are described; the compounds are active as anti-microbial agents.
RELATED APPLICATIONS
This is a division of application Ser. No. 303,254, filed Nov. 2, 1972, now U.S. Pat. No. 3,896,131, which is a continuation-in-part of application Ser. No. 214,409, filed Dec. 30, 1971, now abandoned.
Benzo[ij]quinolizine-2-carboxylic acid derivatives of the general formula [I] and the salts, and their hydrates are provided: ##STR1## wherein A is a methylene group and B is a carbonyl group when A and B are linked by a single bond, or A and B unite together to form a vinylene group when A and B are linked by a double bond, R.sup.1 is a hydrogen atom, a C.sub.1-3 alkyl group or a 2-hydroxyethyl group, R.sup.2 and R.sup.3 are hydrogen atoms, methyl groups or ethyl groups and may be identical to or different from each other, R.sup.3 may be attached to the same carbon atom as R.sup.2, R.sup.4 is a methyl or ethyl group, and X is a halogen atom. The benzo[ij]quinolizine-2-carboxylic acid derivatives and the salts, and their hydrates have good adsorbability from the digestive tract into the circulating blood and exhibit excellent and long-lasting antibacterial activity.
A piperazinylbenzoheterocyclic compound having antimicrobial properties and represented by the formula (I) ##STR1## wherein R.sup.1 represents hydrogen or lower alkyl; R.sup.2 represents hydrogen; R.sup.3 represents hydrogen, lower alkyl, lower alkanoyl, lower alkylsulfonyl, phenylalkyl, benzoyl, p-toluenesulfonyl, a group represented by the formula ##STR2## lower alkyl substituted with one to three of halogen and hydroxy, lower alkanoyl substituted with one to seven of halogen, phenylalkyl substituted with one to three of lower alkoxy on the phenyl ring, lower alkylsulfonyl substituted with one to three of halogen, lower alkenyl or lower alkynyl; R.sup.4 represents hydrogen or halogen, and n is an integer of 0 or 1, except that when n is 0, R.sup.1 and R.sup.2 together can represent the atoms necessary to form a cyclohexane ring, and when R.sup.3 represents lower alkyl substituted with one to three of halogen and hydroxy, lower alkanoyl substituted with one to seven of halogen, phenylalkyl substituted with one to three of lower alkoxy on the phenyl ring, lower alkylsulfonyl substituted with one to three of halogen, lower alkenyl or lower alkynyl, n is 1.
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