A compound of formula (Ie): ** Formula ** or a pharmaceutically acceptable salt thereof, wherein R2 is hydrogen； R4a and R5a, each time they appear, are independently hydrogen, halogen, alkyl or haloalkyl； G1, each time it appears, is independently aryl or heteroaryl, wherein each of the G1 is independently unsubstituted or substituted with 1, 2, 3, 4 or 5 substituents selected from the group consisting of alkyl, alkenyl, alkynyl, halogen , cyano, -G3, -NO2, -OR1b, -O- (CR4bR5b) m-G3, -OC (O) R1b, -OC (O) N (Rb) (R3b), -SR1b, -S (O) R2b, -S (O) 2R2b, -S (O) 2N (Rb) (R3b), -C (O) R1b, -C (O) OR1b, -C (O) N (Rb) (R3b), - C (OH) [(CR4bR5b) m-R4b] 2, -N (Rb) (R3b), -N (Ra) C (O) R1b, -N (Ra) C (O) O (R1b), - N (Ra) C (O) N (Rb) (R3b), - (CR4bR5b) m-G3, - (CR4bR5b) m-NO2, - (CR4bR5b) m-OR1b, - (CR4bR5b) m-OC (O) R1b , - (CR4bR5b) m-OC (O) N (Rb) (R3b), - (CR4bR5b) m-SR1b, - (CR4bR5b) mS (O) 2R2b, - (CR41bR5b) mS (O) 2N (Rb) ( R3b), - (CR4bR5b) mC (O) R1b, - (CR4bR5b) mC (O) OR1b, - (CR4bR3b) m- (C (O) N (Rb) (r3b), - (CR4bR5b) mN (Rb) - (R3b), - (CR4bR5b) mN (Ra) C (O) R1b, - (CR4bR5b) mN (Ra) C (O) O (R1b), - (CR4bR5b) mN (Ra) C (O) N ( Rb) (R3b), cyanoalkyl and haloalkyl； Ra and Rb, whenever they appear, are independently hydrogen, halogen, alkyl or haloalkyl； R1b and R3b, each time they appear, are independently hydrogen, halogen, alkyl or haloalkyl； R2b, each time it appears, is independently alkyl or haloalkyl； R4b and R5b, each time they appear, are independently hydrogen, halogen, alkyl or haloalkyl； m, each time it appears, is independently 1, 2, 3. 4 or 5； G3, each time it appears, is independently aryl or heteroaryl, wherein each of the G3 is independently unsubstituted or substituted with 1, 2. 3, 4 or 5 substituents selected from the group consisting of alkyl, alkenyl, alkynyl, halogen , cyano, -NO2, -OR1b, -OC (O) R1b, -OC (O) N (Rb) (R3b), -SR1b, -S (O) R2b, -S (O) 2R2b, -S (O ) 2N (Rb) (R3b), -C (O) R1b, -C (O) OR1b, -C (O) N (Rb) (R3b), -N (Rb) (R3b), -N
