N-methylene malonate of tetrahydroquinoline and derivatives thereof

DETAILED DESCRIPTION OF THE INVENTION This invention relates to derivatives of 6,7-dihydro-1-oxo-1H,5H-benzo[ij]quinolizine.
The structure and numbering system for this heterocyclic system are shown below: ##SPC1## Referring to the structural formula above, this heterocyclic system may be named and numbered using the position number shown in italics in parenthesis, and that numbering system was used in the specification of application Ser.
No.
214,409, which is the parent of the present application.
However, the system represented by the plain numbers not in parenthesis is believed to be more in accordance with the rules of accepted Chemical Abstracts nomenclature, and this system will be used herein.
The compounds of the invention are carboxylic acids having the formula: ##SPC2## Wherein R is lower alkyl, lower alkoxy, halogen, hydroxy, nitro, cyano, trifluoromethyl, amino, lower alkanamido, trifluoroacetamido or N,N-lower dialkylamino, R is methyl, ethyl or trifluoromethyl, n is an integer from zero to two, and when n is two Y may be methylenedioxy (--OCH.
sub.
2 O--) or ethylenedioxy (--OCH.
sub.
2 --CH.
sub.
2 O--) bonded to adjacent ring positions, m is an integer from zero to two, and when R is trifluoromethyl, m is one; and lower alkyl esters, acyl halides, acyl hydrazides, pharmaceutically acceptable salts or lower alkyl amides, morpholides or piperidides thereof.
"Lower alkyl" or "lower alkoxy" as used herein means alkyl or alkoxy, respectively, having from 1 to 4 carbon atoms in straight or branched chain configuration.
It is well known to the art that pharmaceutically acceptable salts such as alkali metal, alkaline earth, aluminum, iron and other metal and amine salts of pharmaceutically active acids are the equivalents of the acids, and in some cases may even offer advantages in absorption, formulation and the like.
Salts of the free acid compounds of the invention are readily prepared by reaction of the acid with a base and evaporation to dryness.
The base may be organic, e.
g.
sodium methoxide or an amine, or inorganic