N-substituted benzothiophenesulfonamide derivatives

An N-substituted benzothiophenesulfonamide derivative represented by formula (I):

• wherein
• R1 represents a hydrogen atom, a halogen atom or a lower alkyl group;
• R2 represents a lower alkyl group;
• R3 and R4 each may be the same or different and represents a hydrogen atom, a lower alkoxycarbonyl group, a lower alkylsulfonyl group, a benzoyl group, an acyl group having 1 to 4 carbon atoms, a lower alkoxy group, a lower alkoxycarbonylmethylthioacetyl group, a nitro group, —CONHR6 in which R6 represents a hydrogen atom, a lower alkoxycarbonylmethyl group, a carboxymethyl group or —CH(CH2OH)COOR7 which R7 represents a hydrogen atom or a lower alkyl group, a group represented by formula:
• in which R7 has the same meaning as above, a group represented by formula:
• in which R8 and R9 each may be the same or different and represents a hydrogen atom, a lower alkyl group, a lower alkylsulfanyl group, a lower alkylsulfinyl group, a lower alkylsulfonyl group or a lower alkoxycarbonyl group, a hydroxy lower alkyl group, a cyano group or a monocyclic heterocyclic group represented by formulae:
• in which A represents an oxygen atom, a sulfur atom or NH and the dotted part represents a single bond or a double bond provided that the hydrogen atom on the ring may be replaced by a lower alkyl group which may be substituted by a halogen atom, a lower alkoxy group, a hydroxy lower alkyl group, a lower alkoxycarbonyl group or a carboxyl group, provided that at least one of R3 or R4 is
• and
• R5 represents a hydrogen atom, a lower alkoxy group or a lower alkyl group, except the compounds represented by formulae:
• or a pharmaceutically acceptable salt thereof.