Synthesis and Biological Evaluation of Novel Hybrid Molecules Containing Purine, Coumarin and Isoxazoline or Isoxazole Moieties

Scheme 4 Reagents and conditions: (i) TFA (0.2 equiv.), 14 (1.1 equiv.), PIDA (1.1 equiv.) in MeOH, 9d (1 equiv.) in MeOH (dropwise during 1 h), r.t. 4 h.