It should be understood that: when A is a direct bond and B is N then R1 cannot be H; when A is not a direct bond and B is N then R3 cannot be H or a C1-C3 alkyl; when A is a direct bond and B is N and R1 is a 6 member aromatic ring having 0 to 3 substituents independently selected from halogen, fluoromethyl and trifluoromethyl then R4 cannot be a 6 member aromatic ring having 0 to 3 substituents