The preparation of acenaphthyl ene from acenaphthene. I. Review of possible methods

The literature on the preparation of acenaphthylene is reviewed. In view of conflieting reports, previous work on the caustic fusion of acenaphthene monosulphonic acids is re‐examined and the production of acenaphthylene and polyacenaphthylene is confirmed. By photochemical halogenation of accnaphthcnc I‐chloro‐and I‐bromo‐acenaphthene are obtained in good yield. They spontaneously dehydrohalogenate giving a polymeric form of acenaphthylene.