(1) ???C(O)N(R4)2, preferably each R4 is independently selected, more preferably each R4 is independently selected from H or arylalkyl (e.g., ???CH2CH2phenyl), most preferably one R4 is H and the other is arylalkyl, even more preferably one R4 is H and the other R4 is ???CH2CH2phenyl; (2) halo, more preferably 1 to 3 halos independently selected from Br, Cl and F; (3) ???S(O)2R22, more preferably