Compounds for the treatment of SARS

1. A compound of the formula (I):

or a pharmaceutically acceptable salt thereof, wherein:

R 1 is -alkylene-N(H)C(O)CF 3

wherein the alkylene can be substituted with alkyl;

R 2 is alkyl;

R 3 is 3 to 12-membered heterocyclyl; and

R 4 is alkyl;

or a pharmaceutically acceptable salt thereof.

2. The compound of claim 1 , wherein the compound is of formula (Ia):

wherein m is 1.

3. The compound of claim 1 , wherein the compound is of formula (Ib):

4. The compound of claim 1 , wherein the compound is (II), (IIa), or (IIb):

or a pharmaceutically acceptable salt thereof,

wherein:

R 1 is -alkylene-N(H)C(O)CF 3 , wherein alkylene can be substituted with alkyl; and

R 4 is methyl.

5. The compound of claim 1 , wherein R 1 is

6. The compound of claim 1 , wherein R 4 is methyl.

7. The compound of claim 1 , wherein the compound of formula (I) is a compound of the formula:

or a pharmaceutically acceptable salt thereof.

8. The compound of claim 1 , wherein the compound of formula (I) is a compound of the formula:

or a pharmaceutically acceptable salt thereof.

9. The compound of claim 1 , wherein the compound of formula (I) is a compound of the formula:

or a pharmaceutically acceptable salt thereof.

10. The compound of claim 1 , wherein the compound of formula (I) is a compound of the formula:

or a pharmaceutically acceptable salt thereof.

11. A pharmaceutical composition comprising a therapeutically effective amount of one or more compounds of claim 1 and at least one pharmaceutically acceptable excipient.

12. A method for treating a severe acute respiratory syndrome, the method comprising administering a therapeutically effective amount of one or more compounds of claim 1 or a pharmaceutical composition comprising one or more compounds of claim 1 to a patient in need thereof, whereupon the patient is treated for a severe acute respiratory syndrome.

13. The method of claim 12 , wherein the severe acute respiratory syndrome is COVID-19.