1-(3-Methyl-1-phenyl-1H-pyrazol-5-yl)piperazine is an intermediate used to prepare nonracemic γ-bicyclic heteroarylpiperazine- and heteroarylpiperidine-substituted prolinylthiazolidines as selective and orally active dipeptidylpeptidase 4 inhibitors for use as antidiabetic agents.