Synthesis, X-ray molecular structure, and semiempirical calculations of a new heteroarylpiperazine derivative

The new piperazine derivative (1) was synthesized by linking a coumarin sys tem to a heteroarylpiperazine via a propyloxy chain. Its molecular structur e, as determined by X-ray diffractometry is compared to those computed by t hree semiempirical methods. PM3 and MNDO give the best accuracy in reproduc ing the bond distances and angles, respectively. AM1 gives the best agreeme nt with X-ray in reproducing the whole three-dimensional (3D) structure of this molecule. An analysis of these results at the light of other similar p reviously reported is carried out.