Piperic Acid from Piperine, KOH, HCl, MeOH

MistaMiyagi · Dream Team

Borrowed unabashedly from Rhodium's archive of 3base's posts.

Description

To piperine (2g, 0.7mmol, 1eq), 20% of methanolic KOH (100mL) was added and refluxed for 2 days.
After completition of the hydrolysis, methanol was removed
under reduced pressure and a yellow coloured oily solid was obtained.
This residue was dissolved in 50mL water and acidified with 6N HCl to pH<1 yielding a yellowish percipitate of piperinic acid.
Recrystallization from methanol gave yellow needles (0.9g, 60% yield) with a melting point of 206°-208°C.

Reference: Page 69(60) of patent GB2370989, "Piperine Analogues for the Treatment of Skin Conditions", 2002-07-17

Blind Angel · Mon Feb 28, 2005 11:35 am

Hmmm the side product, Piperidine, might be usefull to extract too no, can be used in PCP synthesis i think?

MistaMiyagi · Dream Team

From what I recall of the original source, while piperidine is a side product, it is not present in useful quanitities.

I am sure there must be some way to shift the reaction from one product to the other; however, I do not know what steps to take to exact this.

Regards,
MM