Acetylferrocene

Details:

1. Introduction of Acetylferrocene

 

Acetylferrocene is an organometallic compound based on ferrocene with one acetyl group added to one of the cyclopentadienyl rings. It was originally used in military or space field as an additive in rocket propellant, to promote the burning rate. But nowadays, ferrocenyl derivative has wide applications to biological and medical fields such as ferrocene-modified beta-lactam because of its physiological activity of anti-malarial, anti-tumor, bactericidal, anti-inflammatory, treatment of anemia, inhibition of enzymatic activity and so on by virtue of its unique structure and diverse properties, Good stability, high toxicity; Aromatic, easy for substitution reaction and modification; Hydrophobic, attacking a variety of enzymes in cells, DNA, RNA by going through cell membrane; Strong selectivity by its thickness of the sandwich structure, which can stop it close to the activity site of enzymes; Redox reversibility, which enable it to involve in metabolism by enzymes.  It is typically synthesized from ferrocene and acetic acid anhydride in the presence of an acid catalyst such as phosphoric acid or boron trifluoride.

 

2. Structure descriptors of Acetylferrocene

 

 

 SMILES:O=C(C)\C2=C\C=C/C2[Fe]C/1/C=C\C=C\1

Std. InChI:InChI=1S/C7H7O.C5H5.Fe/c1-6(8)7-4-2-3-5-7;1-2-4-5-3-1;/h2-5H,1H3;1-5H; 

Std. InChIKey:PHMAOJNZIFULOG-UHFFFAOYSA-N

 

3. Preparation of acetylferrocene

 

 

Preparation: Combine 0.4 g of ferrocene, 2 mL of acetic anhydride and 0.5 mL of 85% phophoric acid in a test tube. Stir the mixture well, then heat it in a 60 to 80 oC water bath for 5 minutes. Add an equal volume of crushed ice, stir until the ice has melted, then extract the aqueous suspension with petroleum ether. Dry the solution over anhydrous K2CO3, and decant the dried solution into a clean flask. Check this solution by TLC, using 4:1 petroeum ether / MTBE. You should observe an orange spot for the product at Rf = 0.31, and perhaps a yellow spot for the starting material at Rf = 0.79. Add 0.5 gram of silica gel to the rest of the solution, and evaporate to give a dry orange powder.

 

Purification: Prepare a silica gel column as outlined above, using five grams of silica gel in a 1.9 cm i.d. x 30 cm column. Tap to settle the silica gel, then add the dry orange powder prepared above. Tap to settle, then add a layer of sand. Have fifteen test tubes, each of which can hold at least 5 mL, ready in a test tube rack.

 

Add 75 mL of 4:1 petroeum ether / MTBE in portions to the column. As the solvent moves down the column, you will probably observe a yellow band followed by an orange band. Collect the effluent from the column in 5 mL fractions, and check each of the fractions by TLC (remember, you can often spot three or even four fractions on the same TLC plate). Combine in a tared flask the fractions that have the pure product spot, evaporate the solvent, and record the weight of the product acetylferrocene. Record the melting point and calculate the yield of the reaction. The product may be crystallized by scratching with a little petroleum ether or hexane. The literature m.p.' s of ferrocene and acetylferrocene are 173-174 oC and 85-86 oC respectively.