A compound of Formula I, or an isotopically labeled compound thereof, or a pharmaceutically acceptable salt thereof, in which R 1 and R 2 are each independently selected from the group consisting of cyano, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, acyl, amino, R 9 O-, R 9 S-, R 9 (O=)S-, and R 9 (O=) 2 S-, wherein R 9 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl or heteroaryl; and wherein the alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, acyl, and amino are optionally substituted by one or more substituents wherein the substituents are independently selected from the group consisting of halo, cyano, hydroxy, amino, carboxy, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, =O, =S, -SH, R 10 O-, R 10 S-, R 10 (O=)S-, and R 10 (O=) 2 S-, and wherein R 10 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl; or R 1 and R 2 are taken together to form a ring; R 3, R 4 and R 5 are each independently selected from the group consisting of hydrogen, halogen, hydroxy, carboxy, cyano, amino, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, R 11 O-, R 11 S-, R 11 (O=)S-, and R 11 (O=) 2 S-, wherein R 11 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl or heteroaryl; wherein the alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, acyl, and amino are optionally substituted by one or more substituents wherein the substituents are independently selected from the group consisting of halogen, cyano, hydroxy, amino, carboxy, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, =O, =S, -SH, R 12 O-, R 12 S-, R 12 (O=)S-, and R 12 (O=) 2 S-, and wherein R 12 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl; R 6 and R 6 ' are each independently selected from the group consisting of hydrogen and optionally substituted alkyl; R 7 is selected from the group consisting of hydrogen, alkyl and acyl; wherein the alkyl and acyl are optionally substituted by the following groups: halogen, cyano, hydroxy, amino, carboxy, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, =O, =S, -SH, R 13 O-, R 13 S-, R 13 (O=)S-, and/or R 13 (O=) 2 S-, wherein R 13 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl; R 8 is selected from the group consisting of hydrogen, alkyl and -OC R 14, wherein R 14 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl or heteroaryl; wherein the alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl group is optionally substituted with the following groups: halogen, cyano, hydroxy, amino, carboxy, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, =O, =S, -SH, R 15 O-, R 15 S-, R 15 (O=)S-, and/or R 15 (O=) 2 S-; wherein R 15 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl; and X is an oxygen atom or a sulfur atom or NH R 1 and R 2 are each independently selected from the group consisting of cyano, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, acyl, amino, R 9 O-, R 9 S-, R 9 (O=)S-, and R 9 (O=) 2 S-, wherein R 9 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl or heteroaryl; and wherein the alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, acyl, and amino are optionally substituted by one or more substituents wherein the substituents are independently selected from the group consisting of halo, cyano, hydroxy, amino, carboxy, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, =O, =S, -SH, R 10 O-, R 10 S-, R 10 (O=)S-, and R 10 (O=) 2 S-, and wherein R 10 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl; or R 1 and R 2 are taken together to form a ring; R 3, R 4 and R 5 are each independently selected from the group consisting of hydrogen, halogen, hydroxy, carboxy, cyano, amino, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, R 11 O-, R 11 S-, R 11 (O=)S-, and R 11 (O=) 2 S-, wherein R 11 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl or heteroaryl; wherein the alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, acyl, and amino are optionally substituted by one or more substituents wherein the substituents are independently selected from the group consisting of halogen, cyano, hydroxy, amino, carboxy, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, =O, =S, -SH, R 12 O-, R 12 S-, R 12 (O=)S-, and R 12 (O=) 2 S-, and wherein R 12 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl; R 6 and R 6 ' are each independently selected from the group consisting of hydrogen and optionally substituted alkyl; R 7 is selected from the group consisting of hydrogen, alkyl and acyl; wherein the alkyl and acyl are optionally substituted by the following groups: halogen, cyano, hydroxy, amino, carboxy, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, =O, =S, -SH, R 13 O-, R 13 S-, R 13 (O=)S-, and/or R 13 (O=) 2 S-, wherein R 13 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl; R 8 is selected from the group consisting of hydrogen, alkyl and -OC R 14, wherein R 14 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl or heteroaryl; wherein the alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl group is optionally substituted with the following groups: halogen, cyano, hydroxy, amino, carboxy, acyl, alkyl, heterocyclyl, alkenyl, alkynyl, aryl, heteroaryl, =O, =S, -SH, R 15 O-, R 15 S-, R 15 (O=)S-, and/or R 15 (O=) 2 S-; wherein R 15 is alkyl, heterocyclyl, alkenyl, alkynyl, aryl, or heteroaryl; and X is an oxygen atom or a sulfur atom or NH