# US 11,897,881 B1 · Substituted pyrido[3,4-b]indole-3-carboxylic acids as CK2 inhibitors

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- Number: US 11,897,881 B1
- Document ID: US11897881B1
- Status: Granted
- Kind: B1
- Application number: 18/228,609
- Filed: 2023-07-31
- Granted: 2024-02-13
- Earliest claimed: 2023-07-31
- Assignees: King Faisal University
- Applicants: King Faisal University
- Inventors: Christophe Tratrat; Michelyne Haroun
- Web page: https://patentgrep.com/patent/US11897881B1

## CPC

- C07D 471/04: Ortho-condensed systems
- A61P 35/00: Antineoplastic agents
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS

## Abstract

Pyrido[3,4-b]indole-3-carboxylic acid compounds are provided. The pyrido[3,4-b]indole-3-carboxylic acid compounds have the formula I: wherein Ring A, R1, R2, R3, and R4 are as described herein. The pyrido[3,4-b]indole-3-carboxylic acid compounds inhibit protein kinase CK2 activity and may be used as anticancer and/or antitumor agents, as well as agents for treating inflammation, pain, immunological disorders, diabetes, viral infections, and neurodegenerative diseases.

## Claims

### Claim 1

A compound having the formula I:
or a pharmaceutically acceptable salt or stereoisomer thereof,
wherein:
Ring A is aryl or heteroaryl;
R1 is H, F, or OH;
R2 is H, F, or OH;
R3 is H, halogen, CN, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 cyanoalkyl, C(O)R5, C(O)NR5R6, C(O)OR5, NR5R6, NHC(O)R5, NHC(O)NHR5, NHC(O)OR5, NHS(O)2R5, NHS(O)2NHR5, OR5, S(O)2NR5R6, C3-C6 cycloalkyl, C3-C6 halocycloalkyl, or C3-C6 cyanocycloalkyl;
R4 is H, halogen, CN, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 cyanoalkyl, C(O)R5, C(O)NR5R6, C(O)OR5, NR5R6, NHC(O)R5, NHC(O)NHR5, NHC(O)OR5, NHS(O)2R5, NHS(O)2NHR5, OR5, S(O)2NR5R6, C3-C6 cycloalkyl, C3-C6 halocycloalkyl, or C3-C6 cyanocycloalkyl;
each R5 is independently H, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 cyanoalkyl, C3-C6 cycloalkyl, C3-C6 halocycloalkyl, or C3-C6 cyanocycloalkyl; and
each R6 is independently H, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 cyanoalkyl, C3-C6 cycloalkyl, C3-C6 halocycloalkyl, or C3-C6 cyanocycloalkyl.

### Claim 2 (depends on 1)

The compound of claim 1, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein Ring A is phenyl or pyridinyl.

### Claim 3 (depends on 2)

The compound of claim 2, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:
R3 is H, halogen, C1-C6 alkyl, straight chained C1-C6 haloalkyl, C(O)NR5R6, NR5R6, OR5, or S(O)2NR5R6;
R4 is H, halogen, C1-C6 alkyl, straight chained C1-C6 haloalkyl, C(O)NR5R6, NR5R6, OR5, or S(O)2NR5R6;
each R5 is independently CH3; and
each R6 is independently CH3N.

### Claim 4 (depends on 3)

The compound of claim 3, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:
(i) Ring A is phenyl;
R3 is H; and
R4 is Cl, CH3, CH(CH3)2, CF3, C(O)N(CH3)2, N(CH3)2, OH, OCH3, or S(O)2N(CH3)2; or
(ii) Ring A is phenyl;
R3 is Cl, CH3, CH(CH3)2, CF3, C(O)N(CH3)2, N(CH3)2, OH, OCH3, or S(O)2N(CH3)2; and
R4 is H.

### Claim 5 (depends on 3)

The compound of claim 3, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:
(i) Ring A is pyridinyl;
R3 is H; and
R4 is CH3; or
(ii) Ring A is pyridinyl;
R3 is CH3; and
R4 is H.

### Claim 6 (depends on 3)

The compound of claim 3, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:
Ring A is phenyl;
R3 is CH3; and
R4 is CH3.

### Claim 7 (depends on 1)

The compound of claim 1, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:
(i) R1 is F or OH; or
(ii) R2 is F or OH; or
(iii) R1 is F or OH; and
R2 is F or OH.

### Claim 8 (depends on 7)

The compound of claim 7, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:
(i) R1 is F or OH; and
R2 is H; or
(ii) R1 is H; and
R2 is F or OH.

### Claim 9 (depends on 7)

The compound of claim 7, or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:
(i) R1 is F; and
R2 is F; or
(ii) R1 is OH; and
R2 is OH.

### Claim 10 (depends on 1)

The compound of claim 1, wherein the compound is selected from the group consisting of:
or a pharmaceutically acceptable salt thereof.

### Claim 11 (depends on 1)

A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of the compound of claim 1, or a pharmaceutically acceptable salt or stereoisomer thereof.

### Claim 12

A compound having the formula I:
or a pharmaceutically acceptable salt or stereoisomer thereof,
wherein:
Ring A is phenyl or pyridinyl;
R1 is H, F, or OH;
R2 is H, F, or OH;
R3 is H, halogen, C1-C6 alkyl, straight chained C1-C6 haloalkyl, C(O)NR5R6, NR5R6, OR5, or S(O)2NR5R6;
R4 is H, halogen, C1-C6 alkyl, straight chained C1-C6 haloalkyl, C(O)NR5R6, NR5R6, OR5, or S(O)2NR5R6;
each R5 is independently CH3; and
each R6 is independently CH3;
with the proviso that at least one of R1 and R2 is F or OH.

### Claim 13 (depends on 12)

A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of the compound of claim 12, or a pharmaceutically acceptable salt or stereoisomer thereof.

### Claim 14

A compound selected from the group consisting of:
or a pharmaceutically acceptable salt thereof.

### Claim 15 (depends on 14)

A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of the compound of claim 14, or a pharmaceutically acceptable salt thereof.