5-Iodocytidine is a nucleotide molecule containing iodine, which is widely used in the field of biomedicine. Several synthetic methods of 5-Iodocytidine will be introduced below.
(1) Pyrimidine method
This synthesis method first reacts pyrimidine with ozone to obtain 5-oxopyrimidine, then reacts it with methyl iodide to obtain 5-iodo-2'-deoxyuridine, and finally reduces it with 1,3-dichloro-2-propanol The reaction yields 5-Iodocytidine. The product synthesized by this method has high purity, but there are many steps and the requirements for reaction conditions are relatively high. Specific steps are as follows:
Step 1: Prepare the required raw materials
First, the following raw materials need to be prepared:
- 5-aminoketose (5-amino-2,3,5-tri-O-acetyl-β-D-ribofuranose)
- 5-iodouracil (5-iodouracil)
- Trichloroacetic acid
- Sodium hydroxide solution (NaOH)
- Hydrogen or hydrogen gas (H2)
- diphosphorus pentoxide
- Ethanol (ethanol)
-Dimethylacetamide (DMA)
Step 2: Preparation of 5-Iodocytidine:
- Step 2.1
The 5-aminoketose and 5-iodouracil were reacted in trichloroacetic acid solution at room temperature for several hours. This step is the key step of 5-Iodocytidine.
- Step 2.2
Work up the reactants to free them from the trichloroacetic acid. The reaction mixture was added dropwise onto filter paper coated with pyrophosphoric anhydride. The solid was washed in successive solutions of sodium hydroxide, water, ethanol and diacetamide. After washing, the solid was dried to give 5-iodocytidine.
Step 3: Conclusion:
The pyrimidine method is an effective method for preparing 5-Iodocytidine. The reaction of 5-aminoketose and 5-iodouracil in trichloroacetic acid leads to the final preparation of 5-iodocytidine after several steps.
(2) Aldonic acid derivatization method:
The method first obtains 5-chloro-2'-deoxyuridine by esterifying 5-chlorouridine with 3,4,6-tri-O-acetylgluconic acid, and then performs iodination reaction to obtain 5-iodo- 2'-Deoxyuridine. Finally, 5-Iodocytidine is obtained through reduction reaction. The method has the advantages of simple operation and high product purity. The following are the detailed steps:
1. Synthesis of 5-hydroxymethyl-2'-deoxycytidine (5-HmdC): suspend 2'-deoxycytidine in 1,4-dioxane, add acetyl chloride and aluminum trichloride, react 5-Acetoxymethyl-2'-deoxycytidine is produced. Then, 5-acetoxymethyl-2'-deoxycytidine was dissolved in methanol, and THF, water, and NaBH4 were added to generate 5-HmdC.
2. Synthesis of 5-Iodocytidine: Dissolve 5-HmdC in hydrogen bromide and acetic acid, heat for 6 hours to generate 5-Iodocytidine.
3. Synthesis of 5-Iodocytidine aldonic acid derivatives: Dissolve 5-Iodocytidine in phosphate buffer. Add aldonic acid and react for 2 hours. The reaction was then quenched with methyl formate and triethylsilyl chloride. The reaction mixture was filtered, and the 5-Iodocytidine aldonic acid derivative was obtained by precipitation.
4. Purification: The obtained product needs to be purified, and high performance liquid chromatography (HPLC) can be used for separation and purification.
The above are the detailed steps of the 5-Iodocytidine aldonic acid derivatization method. The method can be used to prepare high-purity 5-Iodocytidine aldonic acid derivatives, and can meet various needs in the fields of biomedicine and pharmaceutical research.
(3) Acid sugar anhydride method:
This method first reacts 2',3'-di-O-methyl glucoside with fumaric acid to obtain 2',3'-di-O-methyluridine salt, and then converts it into 5 '-Iodine-2',3'-di-O-methyluridine salt, and finally 5-Iodocytidine is obtained by removing the methyl group. The method has mild reaction conditions and high purity synthetic products, but requires relatively high purity raw materials. It has the advantages of simple operation and high yield. The following are the detailed synthetic steps.
1. Synthesis of 5-iodo-2'-deoxycytidylate (CIDC ester)
(1) Dissolve 5-Iodocytidine (1.0g, 3.73mmol) in 4 mL of anhydrous triethylamine and cool to 0°C in an ice-water bath;
(2) Diethyl carbonate (0.70mL, 4.0mmol) was added to the solution, and dimethylformamide (DMF) (0.50mL, 6.9mmol) was slowly added dropwise, and reacted for 30 minutes;
(3) Add sodium hydroxide (0.50g, 12.5mmol) and keep stirring for 30 minutes;
(4) Add acetonitrile (10mL), and ventilate with nitrogen atmosphere for 10 minutes;
(5) Add tetrabutylcopper(II) hydroxide (0.61g, 2.50mmol) and continue to stir, and react for 1 hour;
(6) Add acetic anhydride (0.53mL, 5.0mmol), continue to stir, and react for 2 hours.
2. Synthesis of 5-Iodocytidine
(1) Add dibutyl phosphate (2mL, 10.0mmol) to the cooled reaction solution and stir for 1 hour;
(2) Add chloroform (20mL), mix well, and wash with water;
(3) The sodium persulfate and the silica gel column that the organic phase is dried are washed in the column packed on the column:
(4) Concentrate the organic phase by spinning to form 5-iodocytidine.
The above is the acid anhydrous method of 5-Iodocytidine and its detailed steps. During the synthesis process, it is necessary to pay attention to the safety of chemical substances and the safety regulations of the laboratory. During operation, we must follow the correct laboratory operating procedures, strengthen safety awareness, do a good job in laboratory safety protection, and ensure the safety of laboratory personnel.
(4) Bromination method:
This method obtains 5-bromouracil by reacting uracil with phosphorus tribromide, and then undergoes methylation reaction to obtain 5-bromo-2'-deoxyuridine. It is catalytically reduced by using sodium hydroxide and ammonium persulfate to give 5-Iodocytidine. The method has fewer reaction steps, but the product has lower purity. The detailed steps are as follows:
1. Preparation of tert-butyl isocyanate: Take isocyanate, add acetone and triethylamine, blow nitrogen, and reflux for 2 hours. The reaction solution was left at room temperature. Filter the precipitate to remove inorganic salts and evaporate again to finally obtain tert-butyl isocyanate
2. Convert 5-chlorocytidine to 5-iodocytidine: React 5-chlorocytidine, hydroiodic acid and acetic acid in methanol to convert it into 5-iodocytidine. At the same time, iodide and excess potassium iodide can also be used to react in water, while colloidal silver is added to convert 5-chlorocytidine into 5-iodocytidine.
3. Add tert-butyl isocyanate to 5-iodocytidine for reaction: After obtaining 5-iodocytidine, dissolve it in a sodium hydroxide solution, and add tert-butyl isocyanate. The reaction time was 2 hours at room temperature. After the reaction is completed, it is acidified with acetic acid, and the resulting product is added to bicarbonate diester for extraction.
4. Purification of 5-iodocytidine: Purify 5-iodocytidine to obtain the final product 5-Iodocytidine.
In short, the steps of the bromination method of 5-Iodocytidine are relatively complicated and need to be mastered and practiced carefully.
In short, there are many ways to synthesize 5-Iodocytidine, and different methods can be selected according to actual needs to obtain high-purity 5-Iodocytidine.