Tricyclic indole-2-carboxylic acid derivatives

A tricyclic indole-2-carboxylic acid derivative represented by the formula 1:

• ##STR22## wherein X represents an alkyl, halogen or cyano;
• R.sup.1 represents hydrogen, or a protecting group of carboxyl group;
• W represents hydrogen, --CO.sub.2 R.sup.3i, --CONR.sup.3i R.sup.4i,--A--CO.sub.2 R.sup.3i or --A--CONR.sup.3i R.sup. 4i, wherein --A-- represents an alkylene group containing from 1 to 2 carbon atoms and R.sup.3i and R.sup.4i independently represent hydrogen, an alkyl group containing from 1 to 6 carbon atoms, an aryl group containing from 6 to 10 carbon atoms, or a substituted C.sub.6-10 aryl group wherein the substituent on the aryl is selected from the group consisting of alkyl, halogen, --Y--J, or --Z--E, wherein J represents an acidic group which is readily deprotonated in vivo to provide an anion, or a group which is convertible thereto in vivo by hydrolysis, E represents a basic group which is readily protonated in vivo to produce a cation, or a group which is convertible thereto in vivo by hydrolysis, Y represents a single bond, a C.sub.1-6 alkylene, a C.sub.2-6 alkenylene, a substituted C.sub.1-6 alkylene or Y.sup.1 --Q--Y.sup.2, wherein Y.sup.1 represents a single bond or a C.sub.1-6 alkylene, Y.sup.2 represents a C.sub.1-6 alkylene, and Q represents a heteroatom selected from oxygen or sulfur, and Z represents a C.sub.1-6 alkylene;
• wherein the substituent of the term "substituted alkylene" for Y is selected from the group consisting of hydroxy, --OR.sup.3s, --OCOR.sup.3s, amino, --NHCOR.sup.3s, --NHCO.sub.2 R.sup.3s, carboxy, and --CO.sub.2 R.sup.3s, wherein R.sup.3S represents alkyl or C.sub.3-6 alkenyl or a pharmaceutically acceptable salt thereof.