Example:
In their patent on CBDA methyl ester, Mechoulam et al. synthesize CBDA as a precursor to the methyl ester step. CBDA synthesis below:
Synthesis of Cannabidiolic Acid (CBDA):
A mixture of Cannabidiol (CBD, 314 mg, 1 mmol) and 2 molar solution of Magnesium Methyl Carbonate (MMC/2M, 1.5 ml, 3 mmol) in dimethylformamide (DMF) is heated at 130° C. for 3 hours. Then the reaction is cooled to 0° C., acidified with 10% hydrochloric acid and extracted with ether. The organic layer is washed with saline, dried over the drying agent magnesium sulfate (MgSO4) and then evaporated. The crude compound is then cleaned by column chromatography (20% ether-petroleum ether)."
In regards to this posting, look closely at the 1.) acidification step prior to extraction in to ether. They are using 10% HCl which is pH= -0.5. (minus emphasis)
If you want the carboxylic acid in H+ form…this is how you do it.
2.)Then in a second step they back wash the ether with sat’d NaCl before evaporation.
second step confuses me a bit, but it is possible that it is an ion exchage step.
I’m trying to look as this ??? on going.
Comments?