Chemical processes
The chemicals and solvents used were purchased from VWR (Darmstadt) and
used without further purification. Citric acid is food grade
Purchased retail. CBD of high purity (>99%) was obtained from customs seizures
removed. Unless otherwise stated, all reactions were carried out after the expiry of
Reaction time ended by adding aqueous sodium bicarbonate solution.
When toluene was used as a solvent, the organic phase was separated off
washed with deionized water, dried over magnesium sulfate and that
removed under reduced pressure. When using ethanol as a solvent, the
Extract the water-ethanol solution three times with 10 mL of diethyl ether each time and remove the organic phase.
separated, dried over magnesium sulfate and the solvent under reduced pressure
removed. In the case of glacial acetic acid as a solvent, the solution was mixed with 15 g of sodium hydrogen
carbonate neutralized in water. The resulting water-vinegar solution was then used
proceed identically to the water-ethanol solutions. Reactions with citric acid have been reported
carried out in an emulsion of melted CBD and 5 mL of deionized water. The
Processing differs from the other reactions in that the THC is used as
orange mass is deposited, which can only be cleaned externally with deionized
washed in warm water. The amounts of acid used, solvents and their volumes
mina, reaction times and temperatures as well as the amount of CBD used can be found in Table 1
Results and discussion
The identified catalyst-solvent systems were tested (Reactions 1-8, Table 1
and 2) and an initial assessment of their suitability was carried out. Since the total mass is
In all cases, the product mixture corresponded to approximately 80% of the mass of cannabidiol used,
this was neglected as an evaluation criterion. Instead, the criterion was:
Mass fraction of tetrahydrocannabinols (sum of ∆8-THC and ∆9-THC) in the product
mixed as the decisive criterion. This is particularly important because a certain
low THC content in the product despite extensive CBD conversion is a measure of the occurrence
of undesirable side reactions. The second criterion was the proportion of ∆9-THC
the product mixture is considered, as it is the substance with the stronger psychotropic effects
effect and it can be assumed that this is mainly the case
desired reaction product.
Reaction 1, in which a stoichiometric amount of p-toluenesulfonic acid was used,
gave only a low yield. Although almost all of the CBD was consumed, the proportion of
However, THC on the reaction product was the lowest of all reactions. This is due to appearance
a variety of side reactions, so that the reaction product contains by-products such as cannabis
citran, iso-THC and exo-THC occur. These reaction conditions must therefore be considered un-
be assessed appropriately. Reactions 2 and 3, for which different amounts of sulfur
acid used in ethanol provide better results. Reaction 2 also results
only a THC content of 34.6%, here is the small amount of THC but a large Toxichem Krimtech 2023;90(2):112
Residual amount of unused CBD compared to. It can therefore be speculated whether longer
Response times would have improved the result. In addition, the remaining CBD is for the
Consumption probably cheaper than a mixture of different by-products with unrelated
known effect.
Reaction 3 delivers a THC content of 54.5%, but here it occurs again
increased occurrence of by-products. Reaction 4 in glacial acetic acid results in an ambivalent one
Result. On the one hand, a significant amount of ∆9-THC was created, on the other hand, a large amount
number of by-products, some of which are not characterized in more detail. In addition, the complete
Constant removal of acetic acid is difficult and is present in the processed reaction product.
There was a slight smell of vinegar. A chromatographic or distillative purification would therefore be necessary
It is particularly advisable to avoid consumption through smoking. This would be the minimum effort
for a consumable product significantly higher than the other methods tested. When added
a catalytic amount of sulfuric acid to glacial acetic acid at room temperature (reaction 5).
a rapid conversion to ∆8-THC takes place, which makes up almost 80% of the product mixture. About it
In addition, mainly exo-THC is formed. Here too there was a complete separation of the
Acetic acid not possible. Reactions 6 and 7 with p-toluenesulfonic acid (p-TSA) give one
high yield of THC of around 90%, but almost exclusively ∆8-THC. In addition to residual
amounts of CBD, the reaction product contains small amounts of cannabicitran. Reaction 8
produces a THC content of 50.3%, which consists almost 1:1 of ∆8-THC and ∆9-THC.
mensets. The remaining reaction product essentially consists of unreacted CBD
and residues of citric acid. For this reaction it must be emphasized that it is in the hand-
The process is particularly easy since no organic solvents are used
By-products are formed and the product from the reaction mixture is in the form of a
Resin deposits.
Based on the aforementioned criteria, reactions with p-TSA in toluene provided the
best result. The reaction with sulfuric acid in glacial acetic acid also gave good yields
of THC, but with a significantly higher formation of by-products. The reaction in pure
Glacial acetic acid provided the largest amount of ∆9-THC, but was limited in the formation of Toxichem Krimtech 2023;90(2):113
Accompanied by a large number of partially unidentified by-products. Using
Citric acid formed a relatively large amount of THC with a good proportion of ∆9-THC,
however, a lot of CBD was also isolated with the reaction product. This is the reaction
Probably very interesting for users who only plan private consumption
However, users with commercial intentions are relatively uneconomical.
Under the conditions tested, it was found that most reactions in the
Essentially the thermodynamically more stable ∆8-THC was obtained as the end product. The
Reaction system p-toluenesulfonic acid/toluene was selected for further investigation
(Responses 9 to 14). Reaction 10 was carried out with a reduced amount of acid for follow-up
the reaction process. Reactions 12 to 14 took place at room temperature and
corresponded to a reaction regulation that was advertised as particularly beginner-friendly. [16] The
Reaction history was determined by analyzing samples taken during the reaction
tracked using GC-FID.
Source; Berndhäuser & Laußmann
I have tested Method 6 with citric Acid and water, It workerd very well but refluxing 5 hours is a little bit too expensive!
The chemicals and solvents used were purchased from VWR (Darmstadt) and
used without further purification. Citric acid is food grade
Purchased retail. CBD of high purity (>99%) was obtained from customs seizures
removed. Unless otherwise stated, all reactions were carried out after the expiry of
Reaction time ended by adding aqueous sodium bicarbonate solution.
When toluene was used as a solvent, the organic phase was separated off
washed with deionized water, dried over magnesium sulfate and that
removed under reduced pressure. When using ethanol as a solvent, the
Extract the water-ethanol solution three times with 10 mL of diethyl ether each time and remove the organic phase.
separated, dried over magnesium sulfate and the solvent under reduced pressure
removed. In the case of glacial acetic acid as a solvent, the solution was mixed with 15 g of sodium hydrogen
carbonate neutralized in water. The resulting water-vinegar solution was then used
proceed identically to the water-ethanol solutions. Reactions with citric acid have been reported
carried out in an emulsion of melted CBD and 5 mL of deionized water. The
Processing differs from the other reactions in that the THC is used as
orange mass is deposited, which can only be cleaned externally with deionized
washed in warm water. The amounts of acid used, solvents and their volumes
mina, reaction times and temperatures as well as the amount of CBD used can be found in Table 1
Results and discussion
The identified catalyst-solvent systems were tested (Reactions 1-8, Table 1
and 2) and an initial assessment of their suitability was carried out. Since the total mass is
In all cases, the product mixture corresponded to approximately 80% of the mass of cannabidiol used,
this was neglected as an evaluation criterion. Instead, the criterion was:
Mass fraction of tetrahydrocannabinols (sum of ∆8-THC and ∆9-THC) in the product
mixed as the decisive criterion. This is particularly important because a certain
low THC content in the product despite extensive CBD conversion is a measure of the occurrence
of undesirable side reactions. The second criterion was the proportion of ∆9-THC
the product mixture is considered, as it is the substance with the stronger psychotropic effects
effect and it can be assumed that this is mainly the case
desired reaction product.
Reaction 1, in which a stoichiometric amount of p-toluenesulfonic acid was used,
gave only a low yield. Although almost all of the CBD was consumed, the proportion of
However, THC on the reaction product was the lowest of all reactions. This is due to appearance
a variety of side reactions, so that the reaction product contains by-products such as cannabis
citran, iso-THC and exo-THC occur. These reaction conditions must therefore be considered un-
be assessed appropriately. Reactions 2 and 3, for which different amounts of sulfur
acid used in ethanol provide better results. Reaction 2 also results
only a THC content of 34.6%, here is the small amount of THC but a large Toxichem Krimtech 2023;90(2):112
Residual amount of unused CBD compared to. It can therefore be speculated whether longer
Response times would have improved the result. In addition, the remaining CBD is for the
Consumption probably cheaper than a mixture of different by-products with unrelated
known effect.
Reaction 3 delivers a THC content of 54.5%, but here it occurs again
increased occurrence of by-products. Reaction 4 in glacial acetic acid results in an ambivalent one
Result. On the one hand, a significant amount of ∆9-THC was created, on the other hand, a large amount
number of by-products, some of which are not characterized in more detail. In addition, the complete
Constant removal of acetic acid is difficult and is present in the processed reaction product.
There was a slight smell of vinegar. A chromatographic or distillative purification would therefore be necessary
It is particularly advisable to avoid consumption through smoking. This would be the minimum effort
for a consumable product significantly higher than the other methods tested. When added
a catalytic amount of sulfuric acid to glacial acetic acid at room temperature (reaction 5).
a rapid conversion to ∆8-THC takes place, which makes up almost 80% of the product mixture. About it
In addition, mainly exo-THC is formed. Here too there was a complete separation of the
Acetic acid not possible. Reactions 6 and 7 with p-toluenesulfonic acid (p-TSA) give one
high yield of THC of around 90%, but almost exclusively ∆8-THC. In addition to residual
amounts of CBD, the reaction product contains small amounts of cannabicitran. Reaction 8
produces a THC content of 50.3%, which consists almost 1:1 of ∆8-THC and ∆9-THC.
mensets. The remaining reaction product essentially consists of unreacted CBD
and residues of citric acid. For this reaction it must be emphasized that it is in the hand-
The process is particularly easy since no organic solvents are used
By-products are formed and the product from the reaction mixture is in the form of a
Resin deposits.
Based on the aforementioned criteria, reactions with p-TSA in toluene provided the
best result. The reaction with sulfuric acid in glacial acetic acid also gave good yields
of THC, but with a significantly higher formation of by-products. The reaction in pure
Glacial acetic acid provided the largest amount of ∆9-THC, but was limited in the formation of Toxichem Krimtech 2023;90(2):113
Accompanied by a large number of partially unidentified by-products. Using
Citric acid formed a relatively large amount of THC with a good proportion of ∆9-THC,
however, a lot of CBD was also isolated with the reaction product. This is the reaction
Probably very interesting for users who only plan private consumption
However, users with commercial intentions are relatively uneconomical.
Under the conditions tested, it was found that most reactions in the
Essentially the thermodynamically more stable ∆8-THC was obtained as the end product. The
Reaction system p-toluenesulfonic acid/toluene was selected for further investigation
(Responses 9 to 14). Reaction 10 was carried out with a reduced amount of acid for follow-up
the reaction process. Reactions 12 to 14 took place at room temperature and
corresponded to a reaction regulation that was advertised as particularly beginner-friendly. [16] The
Reaction history was determined by analyzing samples taken during the reaction
tracked using GC-FID.
Source; Berndhäuser & Laußmann
I have tested Method 6 with citric Acid and water, It workerd very well but refluxing 5 hours is a little bit too expensive!
