I was in my first semester of Organic chemistry and had recently synthesized aspirin when Graywolf brought THC-O-Acetate to my attention.Our research into Acetate started and we were all very impressed by the outcome of our first reaction
We have since followed this procedure many times with varied efficiency This variability was caused by and directly proportional to the amount of essential oil in the reaction.The more oil the less efficient the reaction. The maximum amount of oil I use is 20g.
When making aspirin, salicylic acid is the raw material for the reaction, Acetic Anhydride is the conjugate and Sulphuric acid (H2SO4) *is the catalyst.
The similarities between Salicylic acid and THCA are the carboxylic acid groups that direct the acetic anhydride to form an ester with the phenolic hydroxyl (OH). In fresh plant material of cannabis, most cannabinoids are present as their carboxylic acid form, known as acidic cannabinoids [Shoyama, 1975].
Since carboxylic acid and hydroxyl groups are polar and hydrophilic, small amounts of THCA are soluble in water. They can be precipitated at a higher PH and made insoluble at a low PH which can be used to our advantage. See our high purity extraction page for more details
When THCA is converted to THC-O- Acetate, the polar C-OH becomes C-O-CH2C=O-CH3. The carboxylic acid group is hydrolyzed (forms water) by the heating with the H2SO4 which reacts with excess Anhydride to produce acetic acid which reacts with regular THC at the hydroxyl group to form more THC-O-Acetate.
Simpler than it sounds, this is a highly efficient reaction, when *catalytic volumes of H2SO4 are added and a Molar excess of acetic anhydride is present.
NOTE THIS DISCLAIMER:
Do not attempt this procedure if you are not qualified or without the proper Chemical fume hood and proper personal protection equipment.
Sulfuric acid is highly corrosive, and Acetic anhydride is not only highly corrosive, but as flammable and explosive as gasoline. Not to mention Hexane is highly flammable and explosive! You should read, understand, and have ready a Material Safety Data Sheet (MSDS) for all chemicals you have.
We neither recommend this procedure or accept any responsibility if you elect to try it yourself.
Materials needed:
- Face shield
- Chemical goggles
- Respirator with acid cartridge
- Chemical apron
- Elbow length gloves
- Fume hood
- Heated Stirrer
- Flat Bottom boiling Flask
- Alhin Reflux condenser
- 5 gal bucket of ice water
- Aquarium water pump
- Pasteur pipette’s
- Beakers of various sizes
- Graduated cylinders
- Coffee filter and funnel
- Glass separatory funnel
Chemicals
- Dry Ice in a foam cooler
- ½ gal 95% Ethyl Alcohol
- ½ gal Denatured alcohol
- Hexane HPLC grade
- 98% Sulphuric acid
- 98% Acetic anhydride (controlled substance)
- 2 gal distilled water
- 200g Kosher salt
- Baking soda
Basic procedure:
- Dry your extract in an oven at 220F until thoroughly dry and free of any alcohols.
- Dissolve your extract into an alkane solvent such as hexane (HPLC grade)
- In a flat bottom boiling flask combine extract in a 1:2.5 w/v ratio of oil to acetic anhydride. (1g + 2.5mL).
- In an ice and water bath; add 2.5 drops/g oil of 98% H2SO4 slowly down the side of the glass swirling gently after every couple of drops.
NOTE: This is where things can hit the fan! You should have proper PPE including a face shield, chemical resistant apron, and elbow length chemical gloves. This again should be done in a certified fume hood by qualified chemists. If you try this and it goes wrong, it’s not our responsibility.
- Once the solution has cooled place a stir bar in carefully to avoid splashes.
- Put on a stir plate and begin stirring vigorously
- Place a reflux condenser onto the top
- Begin heating until the vapor is being condensed at the second bulb. This takes a bit of adjusting to get to the perfect plate temperature versus condenser water flow.
- Start a timer for 60 min for up to 10g and add 60 min for up to an additional 10g of oil.
- Turn off the hot plate but continue to stir
- When cooled slightly add 1mL (/g oil) of distilled water drop wise against the glass.
- Vapors containing acetic acid will escape from the top. This is normal. DO NOT INHALE VAPORS!
- Pour liquid into a separatory funnel, wash flask clean with hexane and pour into funnel. Wash flask of anything left with 95% non-denatured alcohol pour into funnel.
- Prepare 2 gal of distilled water with 100g kosher salt dissolved in each.
- Once the water can be distinguished from the hexane begin draining the water.
- When you are close to the emulsion layer, stop and add salt water until the funnel is almost full.
- Cap and mix by inverting several times, uncap or the pressure will shoot the lid off.
- You should have a lower water layer an emulsion layer and an upper organic layer.
- Continue washing with salt water until both gallons are empty.
- Drain the organic layer into a clean beaker and place into an oil bath @ 250F until dry.
- Test a small drop of acetate on a watch glass with some baking soda dissolved in water. If it fizzes, re-suspend acetate in hexane and wash with baking soda and water until it stops bubbling. Re-separate water from organic in funnel.
- Dry at 250F
- Re-dissolve in 95% Ethanol and place beaker into a shallow, denatured alcohol and dry ice bath for at least 5 min.
- Pour liquid through a coffee filter
- Discard filter and dry the acetate by boiling off the alcohol.
- Wash and dry 2 more times with ethanol
- Enjoy
Attached Photo’s
Cannabis acetate equipment
Washing with saline solution
Separatory funnel
Adding salt water
Filtering through coffee filter.
Final product
Posted by THC vs THCA on April 4, 2013 at 4:20 PM
[...] talking about turning THC back into THCA, I'm talking about turning it into THC-0-A here's a link http://skunkpharmresearch.com/thc-acetate/ Reply With [...]
Posted by Josh Galbraith on February 25, 2013 at 7:34 AM
May I sample some, kind sir, before I take the plunge??
Posted by Skunk Pharm Research,LLC on February 27, 2013 at 8:43 AM
Attend one of our alchemy classes, and you certainly shall.
Posted by Ian h on June 15, 2013 at 6:09 PM
How do we attend these alchemy classes?
Posted by Skunk Pharm Research,LLC on June 16, 2013 at 7:24 AM
Signup sheet at the bottom of http://skunkpharmresearch.com/skunk-pharm-research-classes/
Posted by Julian hinds on February 21, 2013 at 11:02 PM
How to turn it into a powder form
Posted by Skunk Pharm Research,LLC on March 13, 2013 at 6:55 AM
I am not sure. I haven’t done any experimentation in that area.
Joe
Posted by David Johnson on January 22, 2013 at 12:31 PM
HI,
After this process do all of your oil runs come out basically the same? In strength affect and flavor does it still vary strain to strain? How many milligrams of acetate would you say is an appropriate dose? Would you recommend against making oral capsules? I am looking for a way to take a controlled dose that is the same every time with out having to vaporize the oil. My thoughts were to maybe mix the acetate oil with some food oil and put it in a capsule but I read you saying there are down sides to ingesting acetate. As you seem to be very experienced in this I would ask your recommendation on how I should administer my oil. I am also wondering how many doses I would be able to get out of a gram of oil.
Thanks for your time
David
Posted by Skunk Pharm Research,LLC on January 22, 2013 at 4:30 PM
I would say that the variance that occurs is in yield and the taste. The more you wash it with water the better. The freshness has a huge affect on flavor. The bond that is created in this process is more susceptible to oxidation than the hydroxyl or carboxylic acid. So it starts degrading into THC and vinegar very soon after it is exposed to air. If you were to mix it into food or capsules I would suggest doing it while its fresh and mixing in an antioxidant like lemon juice or many other food additives along with an emulsifier. Otherwise be prepared to taste vinegar. Also the dosage is very hard to predict so buckle in for a ride until you get the dosage right. Batch to batch strength will also vary.
Posted by David Johnson on January 24, 2013 at 2:45 PM
I was unaware until reading these comments that oxidization was something I needed to worry about, does it affect the taste when vaporized as well? What is the shelf life of THC acetate at room temperature vs. frozen? Do you have any ballpark as to dosage? How would you compare it to some good waxy BHO?
Posted by Bongstar420 on January 8, 2013 at 11:14 AM
I am having a hard time seeing how you can legally use Acetic anhydride for this application or even afford to procure it with the way OMMP is set up. Isn’t it a federally regulated substance that you have to be approved of for purchase and doesn’t OMMP require no compensation for work and arn’t most OMMP card holders poor anyways? I’ve had the recipe and know how to produce sufficient extracts for years and have been limited due to regulations around chemical procurement in addition to a lack of demand for exotic cannabinoid formulations on top of the fact that an honest person cannot actually follow OMMP law unless they are rich enough to pay for most of the stuff and have enough time to do it, which I am not.
Excellent work anyways, I commend you
Posted by Skunk Pharm Research,LLC on January 9, 2013 at 9:36 AM
Acetic anhydride is not illegal, nor is Cannabis Acetate any more regulated in Oregon, than any other part of the cannabis plant.
They watch you closely when you buy it, because it can also be used to make heroin and explosives, amongst other things. We buy through our business account and keep all of our cards face up on the table. We have been open about our research and I have been publishing instructions for a couple of years now, without interference.
It is also not horribly expensive, and it doesn’t take very much. We are still on our first liter.
As far as compensation, no thoughts on the subject, other than there are no laws in Oregon against charging someone to process their own material and then giving it all back to them. What is illegal, is selling anything from the cannabis plant.
Lastly, Cannabis Acetate is nothing to run shouting its accolades, or dangers through the streets, as it is probably no more potent than its parent stock, it just passes the blood brain barrier faster and arrives all at once.
Posted by fellowextractee on November 26, 2012 at 8:32 PM
Is there any experience in eating the THC Acetate as well? Would you say the effort is worth the product?
Posted by Skunk Pharm Research,LLC on November 27, 2012 at 9:12 AM
We have vaporized and used acetate topically. Both are extremely medically effective for those methods. The down side to ingesting acetate is that it doesn’t have improved flavor over regular extract and since the ester is susceptible to oxidation into thc and acetic acid its probably best in Italian style dressings.
Posted by ryan on August 8, 2012 at 11:17 PM
Very interesting read. How were the effects are they up to snuff with the effects described in cannabis alchemy ?
Posted by Skunk Pharm Research,LLC on August 9, 2012 at 7:45 AM
Because it passes the blood brain barrier so much faster, the acetate arrives all at once, as oppose to coming on, so the effects most certainly make it seem more potent, but I’m not convinced that it is 3X, as presented in Cannabis Chemistry.
Interestingly, despite the CBD also being isomerized into THC, the pain relieving effects when used in a topical, were also greatly enhanced. Less surprising is that the acetate form works better in e-cigarettes using glycerine or propylene glycol, than does the standard non acetate forms of oil.
GW