Benzo[5.6]pyrano[2.3.4-ij]quinolizine and benzo[5.6]thiopyrano[2.3.4-ij]quinolizine derivatives as antibacterial and antineoplastic agents

A compound of formula ##STR31## or a pharmaceutically acceptable salt, ester or amide thereof, wherein:

• A is sulfur or oxygen;
• R.sup.1 is selected from the group consisting of hydroxy, protected-hydroxy, C.sub.1 -C.sub.6 -alkoxy, halo, amino, C.sub.1 -C.sub.6 -alkylamino, hydroxy-C.sub.1 -C.sub.6 -alkylamino, bicyclic nitrogen-containing heterocycle selected from the group consisting of benzopyrrolidine, octahydroisoindole, bicyclo(3,2,2,7-nonane and azabicyclo[3.1.0]hex, nitrogen-containing aromatic heterocycle selected from the group consisting of pyridine, pyrazine, pyrimidine, pyrrole, pyrazole, imidazole, thiazole, oxazole, isooxazole, and nitrogen-containing heterocycle selected from the group consisting of azetidine, pyrrolidine, piperidine, piperazine, morpholine, and thiomorpholine;
• R.sup.2 is selected from the group consisting of hydrogen, halo, C.sub.1 -C.sub.6 -alkyl, and halo-C.sub.1 -C.sub.6 -alkyl;
• R.sup.3 is selected from the group consisting of hydrogen, carboxy-protecting group, C.sub.1 -C.sub.6 -alkyl and C.sub.5 -C.sub.7 -cycloalkyl;
• and
• R.sup.4 and R.sup.5 are independently selected from the group consisting of hydrogen, C.sub.1 -C.sub.6 -alkyl and C.sub.1 -C.sub.6 -alkoxy.