FutureGood Life Gang
2
Jul '19
Mike from @labsociety and I had success salting out THCa, I’ll dig up the SOP and share
THCA
200 g of dried (or ca. 600 g of fresh) flowering tops and leaves of Cannabis sativa (THC type of the “white widow” variety) are extracted with 2 L of isopropanol at <40c. Next the undissolved plant components are removed by filtration. Then the alcohol volume is reduced to ~200 ml by distillation at reduced pressure. 300 ml of heptane is then added to the isopropanol solution. The organic phase is washed twice with 500 ml of 1% saline to remove the alcohol.
This first extract is stirred with 1 L of aqueous 0.1 M sodium hydroxide solution and 1% saline to stop emulsions. Test the pH of the aqueous layer. pH should equal 13.
This second, aqueous extract is separated and treated with a solution of 15 g of citric acid in 150 ml water, whereupon the cannabinoid carboxylic acids precipitate as an oil. Test the pH of the solution. pH should equal 2.
By addition of 2x200 ml heptane and stirring, a third extract is now prepared. Removal of the organic phase and evaporation under reduced pressure at 40° C. yields 15.7 g of an oily residue, which 80% consists of a mixture of the THC acids A and B.
15.7 g of a ca. 80% mixture of THC acids A and B are dissolved in 150 ml isopropanol with stirring and 8.0 g of dicyclohexylamine are added with stirring. 24 hrs stirring at 0°C. produces a thick white precipitate of the dicyclohexylamine salts of the cannabinoid carboxylic acids. Cooling to -10°C with stirring is sometimes necessary to help fully precipitate all salts out of solution. After suction filtration, washing with 50 ml cold isopropanol and drying, 18.7 g of dicyclohexylamine salt of the THC acids with a content of 91% are obtained.
18.7 g of dicyclohexylamine salt of THCA A and B with a content of 91% THC acids in the cannabinoid content are dissolved with stirring in 150 ml of boiling absolute ethanol, and cooled immediately after dissolution has occurred. Stir overnight at 0° C to crystallize out. Cooling to -10°C with stirring is sometimes necessary to help fully precipitate all salts out of solution. Suction filter the white precipitate formed and wash with 50 ml cold absolute ethanol. Yield: 15.5 g of pure white salt with a content of >97% of THC acids (A and B) in the cannabinoid content.
15.0 g of recrystallized dicyclohexylamine salt of the tetrahydrocannabinolic acids A and B are suspended in 200 ml water and over layered with 200 ml hexane. 4 g of citric acid are now added and the mixture stirred until the cannabinoid carboxylic acid salt has completely dissolved. Test the pH of the aqueous phase. pH should equal 2.
The aqueous phase, which now contains the citrate of dicyclohexylamine, is separated and discarded. The hexane phase, which now contains the free tetrahydrocannabinolic acids, is successively washed once with 50 ml of 1% citric acid and three times with 50 ml portions of water. After evaporation of the hexane phase on the water bath at 40° C. under reduced pressure, 9.8 g of amorphous residue of the two positional isomeric tetrahydrocannabinolic acids remain.
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