This paper reports a new and simple procedure
for the synthesis of 3H-spiro[isobenzofuran-1,3?-pyrazole]
derivatives by reacting 1-benzylidene-2-phenylhydrazine
derivatives with ninhydrin in acetic acid medium at
room temperature followed by oxidative cleavage of their
corresponding dihydroindeno[1,2-c]pyrazoles. 1-Benzylidene-
2-phenylhydrazine derivatives were prepared via
the reaction between phenylhydrazine and benzaldehyde
derivatives. Easy procedure, mild reaction conditions, high
yields in short reaction times, availability of starting materials,
and no formation of by-product are the advantages of
this approach.