3-substituted carbonyl-naphtho[2,3-b]furane derivative or pharmaceutically acceptable salt thereof

A compound of Formula (1):

• or a pharmaceutically acceptable salt thereof
• wherein
• X is an oxygen atom, a sulfur atom, or NR7;
• Y is —CO—, —CS—, —SO—, or —SO2—;
• R1 is a hydrogen atom, a halogen atom, a cyano group, a nitro group, an optionally-substituted C1-6, alkyl group, an optionally-substituted C1-6 alkoxy group, an optionally-substituted amino group, an optionally-substituted C1-6 alkylcarbonyl group, an optionally-substituted C3-10 cycloalkyl group, an optionally-substituted C3-10 cycloalkylcarbonyl group, an optionally-substituted 3- to 8-membered saturated heterocyclic group, an optionally-substituted 3- to 8-membered saturated heterocyclic carbonyl group, an optionally-substituted C6-10 aryl group, an optionally-substituted C6-10 arylcarbonyl group, an optionally-substituted 5- to 12-membered monocyclic or polycyclic heteroaryl group, or an optionally-substituted 5- to 12-membered monocyclic or polycyclic heteroarylcarbonyl group;
• R2 is a hydrogen atom, a hydroxy group, an optionally-substituted C1-6 alkyl group, an optionally-substituted C1-6 alkoxy group, an optionally-substituted amino group, an optionally-substituted C3-10 cycloalkyl group, an optionally-substituted 3- to 8-membered saturated heterocyclic group, an optionally-substituted C6-10 aryl group, or an optionally-substituted 5- to 12-membered monocyclic or polycyclic heteroaryl group;
• R3, R4, R5, and R6 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, an optionally-substituted C1-6 alkyl group, an optionally-substituted C2-6 alkenyl group, an optionally-substituted C2-6 alkynyl group, an optionally-substituted C1-6 alkoxy group, an optionally-substituted C1-6 alkylthio group, an optionally-substituted C6-10 arylthio group, an optionally-substituted 5- to 12-membered monocyclic or polycyclic heteroarylthio group, an optionally-substituted C1-6 alkylsulfinyl group, an optionally-substituted C6-10 arylsulfinyl group, an optionally-substituted 5- to 12-membered monocyclic or polycyclic heteroarylsulfinyl group, an optionally-substituted C1-6 alkylsulfonyl group, an optionally-substituted C6-10 arylsulfonyl group, an optionally-substituted 5- to 12-membered monocyclic or polycyclic heteroarylsulfonyl group, an optionally-substituted amino group, an optionally-substituted C1-6 alkylcarbonyl group, an optionally-substituted C3-10 cycloalkyl group, an optionally-substituted C3-10 cycloalkenyl group, an optionally-substituted 3- to 8-membered saturated heterocyclic group, an optionally-substituted C6-10 aryl group, an optionally-substituted 5- to 12-membered monocyclic or polycyclic heteroaryl group, a C1-6 alkylsulfinyl group, an optionally-substituted C3-10 cycloalkylsulfinyl group, an optionally-substituted C1-6 alkylsulfonyl group, or an optionally-substituted C3-10 cycloalkylsulfonyl group;
• and
• R7 is a hydrogen atom, an optionally-substituted C1-6 alkyl group, an optionally-substituted C1-6 alkylcarbonyl group, an optionally-substituted C3-10 cycloalkyl group, an optionally-substituted 3- to 8-membered saturated heterocyclic group, an optionally-substituted C6-10 aryl group, or an optionally-substituted 5- to 12-membered monocyclic or polycyclic heteroaryl group;
• provided that the following compounds are excluded:
• the compounds wherein Y is —CO— and R1 is a methyl group,
• 3-(furan-2-carbonyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• 3-(2-naphthoyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• ethyl 4,9-dioxo-2-(trifluoromethyl)-4,9-dihydronaphtho[2,3-b]furan-3-carboxylate,
• 3-(2,3-dihydrobenzo[b][1,4]dioxine-6-carbonyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• 3-isonicotinoyl-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• 3-(benzo[d][1,3]dioxole-5-carbonyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• 3-(4-methoxybenzoyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• 3-(3,4-dimethoxybenzoyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• 3-benzoyl-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• 3-(4-bromobenzoyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione,
• 2-(trifluoromethyl)-3-(3,4,5-trimethoxybenzoyl)naphtho[2,3-b]furan-4,9-dione,
• 3-(4-fluorobenzoyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione, and
• 3-(thiophene-2-carbonyl)-2-(trifluoromethyl)naphtho[2,3-b]furan-4,9-dione.