18: R= NH,, Xi F yields. The reaction was best run with pure, distilled benzylhydrazine because in situ generation of 11 from the hydrochloride salt gave 13 contaminated with the 2- isomer. Assignment of the structure of 13 as the 1-isomer was established via a NOE experiment. Irradiation of the methylene gave NOE's of 7% and 2% for the aryl and NH2 protons. When the aminopyrazoles 13 and 14 were refluxed with formamide or N- ...