As shown in Scheme X, compound Ip (where X1 and X2 are not hydrogen) can be reacted with 17 or 18 either alone or in the presence of a base such as sodium hydride, sodium hexamethyl disilazide or dimethylaminopyridine in dimethyl formamide or tetrahydrofuran at room temperature or higher to form compounds Iv or Iw respectively which can be reacted with an amine (R7R8NH) at room temperature or high