Thymoquinone is a compound extracted from black grass seeds, with the chemical formula C10H12O2. At room temperature, it is a light yellow oily liquid with a unique irritating odor. Difficult to dissolve in water, easily soluble in organic solvents such as ethanol and ether. Has a unique irritating odor. Difficult to dissolve in water, but can dissolve in organic solvents such as ethanol, ether, and chloroform. It has inhibitory effects on various bacteria, including Gram positive and Gram negative bacteria. This compound exerts antibacterial effects by interfering with bacterial metabolic processes or damaging bacterial cell walls. It has also been studied for use in oral care products, such as mouthwash, toothpaste, etc. It can inhibit the growth of bacteria in the oral cavity and reduce the occurrence of oral diseases such as oral ulcers and gingivitis.
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This method involves a process of synthesizing Thimoquinone through multi-step reactions starting from 6-oxo isophorone. This method has the advantages of simple operation, easy availability of raw materials, and high product purity.
Synthesis steps:
1. Dehydration during aldol condensation
Using acetone and formaldehyde as raw materials, a aldol condensation reaction occurs under weak alkaline conditions (such as NH4OH, NaOH, etc.), generating α-β Unsaturated butenone. The main chemical equation for this step is as follows:
R-CHO+CH3-CO-R '→ R-CH=CH-R'+H2O
2. 1,2-Nucleophilic addition reaction
Apply the results obtained from the previous step α-β Unsaturated butene ketone undergoes a 1,2-nucleophilic addition reaction with acetylene under acidic conditions (such as HCl, H2SO4, etc.) to produce hexacarbyne tertiary alcohol. The corresponding chemical equation is as follows:
R-CH=CH-R '+HC ≡ CH → R-CH (OH) - CH2-C ≡ CH
3. Reordering reaction
Under the action of sulfuric acid, hexaacetylene tertiary alcohol undergoes rearrangement reaction to generate the target compound. The chemical equation for this step is as follows:
R-CH (OH) - CH2-C ≡ CH+H2SO4 → R-C (OH)=C (OH) - C ≡ CH
4. Protecting hydroxyl groups
To ensure that the hydroxyl groups are not reacted off in subsequent steps, we use esterification or etherification to protect the hydroxyl groups. Common protective agents include formic acid, methanol, ethyl acetate, etc. The corresponding chemical equation is as follows:
R-C (OH)=C (OH) - C ≡ CH+R'OH → R-C (OR ')=C (OR') - C ≡ CH+H2O
5. Reaction with 6-oxo isophorone
React the product obtained in the previous step with 6-oxo isophorone under weak acid or weak base conditions to form the intermediate of Thimoquinone. The corresponding chemical equation is as follows:
R-C (OR ')=C (OR') - C ≡ CH+6-O-C (R ")=O → R-C (OR ')=C (OR') - C (R")=O+R'COOH/R "COOH
6. Bilateral Wittig reaction
Under the action of strong bases (such as NaOH, KOH, etc.), a bilateral Wittig reaction is carried out on the intermediate to ultimately synthesize thymoquinone. The chemical equation for this step is as follows:
R-C (OR')=C (OR') - C (R")=O+Ph3P=CHCOOEt → Ph3P=CR'- CH (OR')=CR'COOH+Ph3P=O+EtOH
7. Post treatment and purification
By means of extraction, distillation, and recrystallization, the product is purified to obtain high-purity Thymoquinone. The specific post-processing methods can be selected according to actual needs.
BASF has adopted a unique synthesis method to prepare Thimoquinone, which involves protecting hydroxyl groups, conversion with 6-oxo isophorone, and rearrangement during the conversion process.
Synthesis steps:
1. Hydroxyl protection
Firstly, protect the hydroxyl group of the intermediate hexaacetylene tert alcohol, commonly used protectants include esterification or etherification reagents. For example, formic acid, methanol, or ethyl acetate can be used for protection. The corresponding chemical equation is as follows:
R-CH (OH) - CH2-C ≡ CH+R'OH → R-CH (OR ') - CH2-C ≡ CH+H2O
2. React with 6-oxo isophorone
React the protected hydroxyl group with 6-oxo isophorone under specific conditions. The purpose of this step is to connect 6-oxo isophorone to hexaacetylene tert alcohol while maintaining the protective state of the hydroxyl group. The corresponding chemical equation is as follows:
R-CH (OR ') - CH2-C ≡ CH+6-O-C (R ")=O → R-CH (OR')=C (OR") - C (R ")=O+R'COOH/R" COOH
3. Reordering during the conversion process
During the reaction process, intermediates may undergo rearrangement reactions, which are mainly achieved through intramolecular reactions or interactions with other functional groups. The specific rearrangement method depends on the reaction conditions and the structure of the intermediate. The rearranged chemical equations may be more complex and need to be written according to actual situations.
4. Remove protection and product separation
Finally, the previously protected hydroxyl group is deprotected under specific conditions to obtain the target product, Thimoquinone. This step can be deprotected through methods such as hydrolysis, reduction, or acid/base catalysis, and the specific method needs to be selected based on the actual protective group. After deprotection, Thimoquinone can be separated and purified to obtain high-purity products.
The main route for synthesizing astaxanthin in China is to α- Using violet ketone as the raw material, astaxanthin is finally synthesized through a series of chemical reactions. This method has the advantages of easy availability of raw materials, mild reaction conditions, and high product purity.
Synthesis steps:
1. Treatment with m-chloroperoxybenzoic acid
Firstly, integrate α- Violet ketone reacts with m-chloroperoxybenzoic acid and undergoes oxidation to α- A hydroxyl group is introduced on the side chain of violet ketone to form an intermediate. The purpose of this step is to provide the necessary functional groups for subsequent chemical reactions. The chemical equation is as follows:
(CH3) 2C=CHCH2CH2CHO+(COCl) 2 (CCl4) → (CH3) 2C=CHCH2CH2COOH+(COCl) 2 (COOH)
2. Intermediate conversion
The generated intermediate undergoes a series of transformation processes, such as esterification, hydrolysis, etc., with the aim of transforming the intermediate into a form that is easier to carry out subsequent reactions. The specific steps and chemical equations of these transformation processes need to be written according to the actual situation.
3. Acid rearrangement
Under the action of hydrobromic acid, the intermediate undergoes acidification rearrangement reaction. The purpose of this step is to further adjust the molecular structure through rearrangement reactions, in preparation for subsequent reactions. The specific chemical equations need to be written according to the actual situation.
4. Interaction with triphenylphosphine
The intermediate reacts with triphenylphosphine to produce pentadecane triphenyl quaternary phosphonium salt. The purpose of this step is to introduce specific functional groups through the reaction with triphenylphosphine, in preparation for subsequent reactions. The specific chemical equations need to be written according to the actual situation.
5. Bidirectional Wittig reaction
Finally, the quaternary phosphonium salt was converted to astaxanthin through a bidirectional Wittig reaction. The key to this step is to ensure the smooth progress of the Wittig reaction and achieve a high yield. The specific chemical equations need to be written according to the actual situation.