Coumarin derivative having antitumor activity

A compound represented by general formula (11) below or a pharmaceutically acceptable salt thereof:

• wherein:
• G1 and G2 are each independently —CR1═;
• G3 is CR1;
• G8 is —C(-G9—X)═;
• X is a C1-6 alkyl group (where the C1-6 alkyl group may optionally be substituted with a group selected from a halogen atom, a hydroxy group, a cyano group and —NR56R57), an aryl group, a heterocyclic group, R31CS—, R31CO—, R33R34NCS—, R33R34NC═NH—, R3R4NCO— or R33R34NCO2—;
• G9 is a single bond, an oxygen atom, a sulfur atom, —(CR35R36)l— (where l represents an integer of 1 to 3) or —NR37—;
• Ring G6 is a 6-membered nitrogen containing hereroaryl,
• A is a group represented by general formula (2) below or a group represented by general formula (3) below:
• G4 is an oxygen atom or a sulfur atom and G5 is an oxygen atom;
• G7 is, —CR42R43—
• R1 is a hydrogen atom, a halogen atom, a cyano group, a C1-6 alkyl group (where the C1-6 alkyl group may optionally be substituted with a group selected from a halogen atom, a hydroxy group and —NR46R47), a C2-7 alkenyl group, a carbamoyl group or a C2-7 alkynyl group (where the C2-7 alkynyl group may optionally be substituted with a C1-4 acyl group);
• R2 is a hydroxy group, a C1-6 alkoxy group, —NR48R49 or a C1-6 alkyl group (where the C1-6 alkyl group may optionally be substituted with a group selected from a halogen atom, a hydroxy group, a C1-6alkoxy group, a formyl group, —CO2R50 and —CO2NR51R52);
• R3, R4, R6, R7, R9, R10, R31, R46 and R47 are each independently a hydrogen atom, a C1-6 alkoxy group, a C3-8 cycloalkyl group or a C1-6 alkyl group (where the C1-6 alkyl group may optionally be substituted with a group selected from a cyano group, a halogen atom, a hydroxy group, a C1-6 alkoxy group, —NR13R14, —CONR28R29 and an aryl group);
• R33 and R34 are each independently a hydrogen atom, a C1-6 alkyl group or an aryl group;
• the combination of R3 and R4, combination of R6 and R7, combination of R9 and R10, combination of R33 and R34, and combination of R46 and R47 may form, together with the nitrogen atom to which they are bonded, a 4- to 6-membered heterocyclic group having at least one nitrogen atom (where the heterocyclic group may optionally be fused with a benzene ring);
• one R35 group and one R36 group are each independently a hydrogen atom, a halogen atom or a C1-6 alkyl group;
• R13,R14,R56 and R57 are each independently a hydrogen atom, a C1-6 alkyl group, —COR32 or —CO2R32;
• and
• R5, R8, R28, R29, R32, R37, R48, R49, R50, R51, and R52 are each independently a hydrogen atom or a C1-6 alkyl group;
• R42 and R43 are hydrogen.