Hello Narottam Mukhopadhyay

Check this one. May be it is helpful.

Dear Narottam, thank you for asking this very interesting technical question. In gerenal, oxidation with AgBF4 should work. I found a detailed procedure in which the reaction of acetylferrocene with silver tetrafluoroborate is reported. It is the freely accessible Supplementary Information to the paper entitled "Ferrocenium promoted oxidation of benzyl amines to imines using water as the solvent and air as the oxidant". The synthesis of acetylferrocenium tetrafluoroborate is described on page S4. I hope it works.

Good luck and best wishes, Frank Edelmann

Dear Narottam, P.S.: Alternatively you can try the oxidation reaction of acetylferrocene with anhydrous iron(III) chloride, FeCl3. This method was described in the less known journal Collection of Czechoslovak Chemical Communications, 1966, Volume 31, Pages 1985-91. I don't have access to the full text of this article entitled "Acetylferricinium salts", but the synthesis is briefly described in the Abstract: "To prepare acetylferricinium tetrachloroferrate, [C5H5FeC5H4Ac]+FeCl4-, to 100 mL. of 0.01 M acetylferrocene in anhydrous diethyl ether add an ether solution of freshly sublimed FeCl3 as long as a precipitate forms, filter, wash the blue-green precipitate with MeOH and recrystallize from absolute ethanol." However, I think that the AgBF4 reaction is more convenient (if it works).

Dear Sir ( Frank T. Edelmann )

Thank you for the references.

I have exactly followed the first one with AgBF4. At first, a greenish-blue solid separated, but after 10 mins, it became brown and insoluble in every known solvent.

I have tried this reaction in different time frames, but I got that brown insoluble junk every time.

All I can conclude, this reaction isn't stable in the air. Maybe the glove box can help.

However, I have tried to buy this product, but it's not showing anywhere from my country (India).

Dear Aqsa Nazir

Thanks, but I am searching for the procedure of acetylferrocinium salt. I already have acetylferrocene with me.

Dear Narottam, thank you for ypur response and explanation. To my knowledge the ferrocenium salts are not really sensitive to dry oxygen, because they are prepared by oxidation reactions and already contain trivalent iron. The main problem with these compounds is their sensitivity towards moisture. The observation that you first obtained a greenish-blue solid shows that the reaction worked, but then the product decomposed due to the presence of moisture (hydrolysis).So what you should do is make sure that both the diethyl ether and the dichloromethane used in the reaction are rigorously dried prior to use. Diethyl ether should be dried over sodium / benzophenone and dichloromethane over calcium hydride. In any case it's worth trying the reaction again with carefully dried solvents under inert atmosphere.

Thank you very much, Sir. Frank T. Edelmann