Rosocyanine Synthesis (+ Curcumin Extraction)
Rosocyanine is an interesting organoboron compound that seems to have very little information about it despite how easy it is to make. In solution, it
is a strong, vibrant red color. When isolated, it is an unstable, shiny green solid.
Required Materials
(Concentrations listed below are just what I used, and you can probably get away with using more concentrated or less concentrated chemicals.)
- Turmeric Powder
- 91% Isopropyl Alcohol
- Boric Acid
- 32% HCl
Step 1 - Curcumin Extraction from Turmeric
To a test tube, I added a very small amount (in the tens of milligrams) of turmeric powder. I also dropped in a stir bar. To the test tube, I pipetted
in 91% isopropanol until I felt that there was enough to dissolve all of the curcumin. The IPA took on a bright yellow color due to the curcumin
dissolving. I stirred this for 10 minutes to ensure everything was in solution. Finally, I allowed the leftover turmeric powder to settle at the
bottom of the test tube and decanted the yellow solution into a 50ml beaker.
Step 2 - Curcumin to Rosocyanine
To the 50ml beaker with my curcumin solution, I spooned in a small amount of boric acid and allowed it to dissolve. Next, I pipetted in an excess of
32% hydrochloric acid. The HCl serves two purposes: It provides chloride ions to the reaction, and the acidity keeps the product in solution. The
excess will ensure that there is enough HCl leftover after the reaction to keep the PH low. After the addition of the hydrochloric acid, the solution
almost immediately became a deep red color. I allowed this solution to stir for another 10 minutes to ensure everything was done reacting. Finally, I
stored the Rosocyanine solution in a 2 dram vial.
  
[Edited on 1-7-2021 by GreenJames]
[Edited on 1-7-2021 by GreenJames]
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