Fluorene → 2-Acetylfluorene

Participants

Reaction Steps

Fluorene is acylated by acetic anhydride in an organic solvent, e.g., chlorobenzene in the presence of aluminum chloride at 18°-20° C at the initial stage of the process followed by heating to 40°-50° C to obtain 2-acetylfluorene at a yield of up to 74 weight percent. The latter is oxidized by chromic acid or by the salts thereof in an acetic acid medium at 50°-90° C for 4-12 hours to obtain 2-acetylfluorenone in a yield of 27-68 weight percent as calculated for 2-acetylfluorene, or 20-50 weight percent when calculated for fluorene. The resultant product is brominated in an organic solvent, e.g., chloroform at 50°-60° C or in acetic acid at 100°-110° C. The yield of the thus-formed 2-ω-dibromoacetylfluorenon equals 71-88 weight percent as calculated for 2-acetylfluorenone, or 35.4-44 weight percent when calculated for fluorene. Then 2-ω-dibromoacetylfluorenone is made to react with morpholine when heated to 50°-98° C for 1-2 hours to obtain 2-ω-bismorpholinoacetylfluorenone in a yield of 40-85 weight percent as calculated for 2-ω-dibromoacetylfluorenone, or 17.6-37.4 weight percent when calculated for fluorene.

Provenance & Evidence