Patent ID: 7985764

Claim:
A compound represented by the following formula (I-b) or a pharmaceutically acceptable salt thereof wherein [symbols in the formula have the following meanings; R 1 : —N═C(NH 2 ) 2 , —N(R 0 )-(nitrogen-containing saturated heterocyclic group which may be substituted), —N(R 0 )-lower alkylene-N(lower alkyl) 2 , —N(R 0 )-lower alkylene-(nitrogen-containing saturated heterocyclic group which may be substituted), —N(R 0 )-lower alkylene-(heterocyclic group substituted with —N(lower alkyl) 2 ) or —N(R 0 )-lower alkylene-(cycloalkyl substituted with —N(lower alkyl) 2 ), R 0 : each independently —H or lower alkyl, wherein (I) when R 1 is —N═C(NH 2 ) 2 , then [R 2 : —H, lower alkyl, halogeno-lower alkyl, cycloalkyl, aryl, heterocyclic group, —CH(aryl) 2 or lower alkylene-R 21 , wherein the aryl and heterocyclic group in R 2 may be respectively substituted, R 21 : —OR 0 , —O-aryl, —N(R 0 ) 2 , —CH(OH)R 0 ,—C(O)R 0 , —C(O)-aryl, —CO 2 R 0 , —C( 0 )N(R 0 ) 2 , cycloalkyl, aryl, heterocyclic group or CH(aryl) 2 , wherein the aryl and heterocyclic group in R 21 may be respectively substituted, R 3 and R 4 : —H, lower alkyl, halogeno-lower alkyl, lower alkylene-OR 0 , lower alkylene-N(R 0 ) 2 , —O-lower alkyl, —S-lower alkyl, —S(O)-lower alkyl, —S(O) 2 -lower alkyl, —C(O)R 0 , —CO 2 R 0 or —C(O)N(R 0 ) 2 , and the substituting position of —C(O)R 1 may be any position on the benzene ring, with the proviso that, R 2 is —H, methyl, isopropyl or unsubstituted benzyl, at least one of R 3 and R 4 is not —H], and (II) when R 1 is —N(R 0 )-(nitrogen-containing saturated heterocyclic group which may be substituted), —N(R 0 )-lower alkylene-N(lower alkyl) 2 ,) —N(R 0 )-lower alkylene-(nitrogen-containing saturated heterocyclic group which may be substituted), —N(R 0 )-lower alkylene-(heterocyclic group substituted with -N(lower alkyl) 2 ) or —N(R 0 )-lower alkylene-(cycloalkyl substituted with —N(lower alkyl) 2 ), then [R 2 : lower alkylene-aryl or lower alkylene-heterocyclic group, wherein the aryl and heterocyclic group in R 2 may be respectively substituted, R 3 and R 4 : lower alkyl, lower alkylene-OR 0 , —C(O)R 0 , —S-lower alkyl, —S(O)-lower alkyl or —S(O) 2 -lower alkyl, and the substituting position of —C(O)R 1 is at the para-position of N(R 2 )], with the proviso that 1-benzyl-N-[2-(dimethylamino)ethyl]-2,3-dimethyl-1H-indole-5-carboxamide is excluded].