PARTIALLY FLUORINATED HETEROCYCLIC COMPOUNDS. PART 24. A PLAUSIBLE MECHANISM FOR THE FORMATION OF THE FISCHER INDOLE PRODUCT FROM ACETOPHENONE 1,3,4,5,6,7,8,-HEPTAFLUORO-2-NAPHTHYLHYDRAZONE IN WHICH o-FLUORINE IS LOST

Article abstract of DOI:10.1016/S0022-1139(00)81061-1

Acetophenone 1,3,4,5,6,7,8,-heptafluoro-2-naphthylhydrazone (1) reacts in tetralin at reflux to give 4,5,6,7,8,9,-hexafluoro-2-phenylbenzindole (2) as the major product, accompanied by other materials including acetophenone 3,4,5,6,7,8,-hexafluoro-2-naphthylhydrazone (4) which is proposed as the true precursor to the Fischer indole product (2) since it gives (2) under the same conditions.The presence of α-tetralone in the reaction mixture provides the clue to a reductive elimination of F^- from (1).