Indole derivatives, salts thereof, and congestive heart failure therapeutic agents comprising the same

A pharmaceutical composition, comprising:

• (i) an effective amount of the indole derivative of formula (1) ##STR21## wherein at least one of R.sup.1, R.sup.2, R.sup.3, or R.sup.4 is a lower alkyl or alkenyl group which may have substituents selected from halogen atoms, hydroxy group, alkylsulfonyloxy groups, alkylsilyloxy groups, azido group, cyano group, amino group, alkylamino groups having 1-8 carbon atoms, dialkylamino groups having 2-16 carbon atoms, phenyl alkylamino groups having 7-12 carbon atoms, alkanoylamino groups having 1-6 carbon atoms, alkoxycarbonylamino groups having 2-10 carbon atoms, pyrrole, pyrrolidine, imidazole, imidazoline, oxazole, oxazoline, thiazole, thiazoline, piperidine, piperazine, and morpholine (wherein these cyclic amino groups may further contain substituents selected from alkyl or alkenyl groups having 1-8 carbon atoms, phenyl alkyl groups having 7-15 carbon atoms, alkanoyl groups having 1-6 carbon atoms, benzoyl group, alkoxybenzoyl groups having 1-8 carbon atoms, and di(C.sub.1-8)alkoxybenzoyl groups), and others represent a hydrogen atom or an alkyl group;
• R.sup.5 and R.sup.6 individually represent a hydrogen atom, a halogen atom, a lower alkyl or acyl group, or a lower alkyl group which may have substituents selected from hydroxy group, halogens, cyano group, alkoxycarbonyl groups, and carboxy groups;
• R.sup.7 may either represent a hydrogen atom or a benzyl group, or form a double bond with A;
• and R.sup.8 and R.sup.9 individually represent a hydrogen atom, a halogen atom, a hydroxy group, or a lower alkyl group which may have substituents selected from hydroxy group, halogens, cyano group, alkoxycarbonyl groups, and carboxy groups, or R.sup.8 and R.sup.9 may together represent an oxygen atom, an alkenyl group, or either one of R.sup.8 and R.sup.9 may form a double bond with A;
• and A represents a group ##STR22## wherein R.sup.10 is a hydrogen atom or a lower alkyl group;
• and the dotted line indicates that the bond may be a double bond;
• or a pharmaceutically acceptable salt thereof;
• and
• (ii) a pharmaceutically acceptable carrier.

A method of treating a patient suffering from congestive heart failure, which comprises administering an effective amount of an indole derivative of formula (1) to said patient ##STR25## wherein at least one of R.sup.1, R.sup.2, R.sup.3, or R.sup.4 is a lower alkyl or alkenyl group which may have substituents selected from halogen atoms, hydroxy group, alkylsulfonyloxy groups, alkylsilyloxy groups, azido group, cyano group, amino group, alkylamino groups having 1-8 carbon atoms, dialkylamino groups having 2-16 carbon atoms, phenyl alkylamino groups having 7-12 carbon atoms, alkanoylamino groups having 1-6 carbon atoms, alkoxycarbonylamino groups having 2-10 carbon atoms, pyrrole, pyrrolidine, imidazole, imidazoline, oxazole, oxazoline, thiazole, thiazoline, piperidine, piperazine, and morpholine (wherein these cyclic amino groups may further contain substituents selected from alkyl or alkenyl groups having 1-8 carbon atoms, phenyl alkyl groups having 7-15 carbon atoms, alkanoyl groups having 1-6 carbon atoms, benzoyl group, alkoxybenzoyl groups having 1-8 carbon atoms, and di(C.sub.1-8)alkoxybenzoyl groups), and others represent a hydrogen atom or a lower alkyl group;

• R.sup.5 and R.sup.6 individually represent a hydrogen atom, a halogen atom, a lower alkyl or acyl group, or a lower alkyl group which may have substituents selected from hydroxy group, halogen, cyano group, alkoxycarbonyl groups, and carboxy groups;
• R.sup.7 may either represent a hydrogen atom or a benzyl group, or form a double bond with A;
• and R.sup.8 and R.sup.9 individually represent a hydrogen atom, a halogen atom, a hydroxy group, or a lower alkyl group which may have substituents selected from hydroxy group, halogens, cyano group, alkoxycarbonyl groups, and carboxy groups, or R.sup.8 and R.sup.9 may together represent an oxygen atom, an alkenyl group, or either one of R.sup.8 and R.sup.9 may form a double bond with A;
• and A represents a group ##STR26## wherein R.sup.10 is a hydrogen atom or a lower alkyl group;
• and the dotted line indicates that the bond may be a double bond;
• or a pharmaceutically acceptable salt thereof.