Hydrochloric Acid → HCID 15037285, compound

Participants

Reaction Steps

2,4,7-Trifluoro-5-nitrofluorene was oxidized to the fluorenone using sodium dichromate in acetic acid and then reduced to 5-amino-2,4,7-trifluorofluorenone using tin(II)chloride in a mixture of ethanol and concentrated hydrochloric acid. The amine was converted to the 5-diazonium tetrafluoroborate salt by treatment with sodium nitrite in a mixture of tetrahydrofuran and aqueous fluoroboric acid. The material was allowed to react with potassium ethyl xanthate in a hot mixture of water and toluene to provide ethyl 2,4,7-trifluoro-9oxofluoren-5-yl xanthate which was then hydrolyzed using ethanolic sodium hydroxide and S-methylated with methyl iodide to give 2,4,7-tri-fluoro-5-methylthiofluorenone. Hydantoin formation was accomplished by heating an ethanol solution of the ketone, potassium cyanide, ammonium carbonate at 115° C. for 15 hours.

Provenance & Evidence