A kind of preparation method of 3', 5'-di-oxygen-(4-p-methylbenzoyl)-β-l-thymine
A technology of methylbenzoyl and thymine, which is applied in the field of synthesis and preparation of organic compounds, can solve the problems of poor selectivity of β products, low product yield, complicated post-treatment, etc., shorten the reaction time, simplify the reaction steps, avoid Yield reduction effect
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Embodiment 1
[0033] The specific steps for preparing 3',5'-di-oxo-(4-p-methylbenzoyl)-β-L-thymine are:
[0034] 1) Preparation of hydroxyl-protected thymine: add 36 g of thymine, 63 g of hexamethyldisilazane, 0.6 g of ammonium sulfate and 31 g of toluene into a 250 mL three-neck flask with a reflux condenser, mix, and replace with nitrogen three times , heat up, reflux for 4 hours, cool down to 75°C, concentrate, and use 100g of toluene as a solvent twice, take out hexamethyldisilazane by steaming toluene, and take samples from the remaining concentrated solution until the test result does not contain hexamethyldisilazane Alkane, 78g of thymine protected by hydroxyl group was obtained.
[0035] 2) Chlorosugar and glycosidation reaction: add 100g of 3,5-di-oxo-p-methylbenzoyl-2-deoxy-α,β-L-methylfuranoside, 125g of methyl tertiary furanoside to a 2L three-necked bottle Butyl ether and 710g of chloroform, stir to dissolve, lower the temperature to 5°C, slowly add 33.2g (3.5 equivalents) of hy...
Embodiment 2
[0039] 1) Preparation of hydroxyl-protected thymine: same as Example 1.
[0040] 2) Chlorosaccharides and glycosidation reaction: Add 100g of 3,5-di-oxo-p-methylbenzoyl-2-deoxy-α,β-L-methylfuranoside, 125g of diethyl ether and 175g of chloroform, stir to dissolve, cool down to 22°C, slowly pass through 475g of 6% hydrogen chloride acetic acid solution (3 equivalents) to carry out chlorosugar reaction, through HPLC detection, when the mass content of raw materials is less than 20%, add step 1) Prepared 78 g of hydroxy-protected thymine, stirred and reacted at 20°C, and after 3 hours, a sample was taken to detect that the mass content of the raw material was 1%, the reaction was completed, and a crude product reaction solution was obtained.
[0041] 3) Quenching the reaction to obtain the crude product: Add 5 g of absolute ethanol and 10 g of deionized water to the above crude product reaction solution slowly and successively to quench the reaction, add 0.1 mol / L hydrochloric ac...
Embodiment 3
[0044] 1) Preparation of hydroxyl-protected thymine: same as Example 1.
[0045] 2) Chlorosaccharides and glycosidation reaction: Add 100g of 3,5-di-oxo-p-methylbenzoyl-2-deoxy-α,β-L-methylfuranoside, 50g of methyl tert-methylfuranoside to a 2L three-necked bottle Butyl ether and 710g of dichloromethane were stirred and dissolved, cooled to 45°C, and 11.37g (1.2 equivalents) of hydrogen chloride gas was slowly introduced to carry out the chlorosugar reaction. It was detected by HPLC. When the mass content of raw materials was less than 20%, add Step 1) Prepare 78 g of hydroxy-protected thymine, stir and react at 40° C., take a sample after 3 hours by HPLC to detect the mass content of the raw material is 0.72%, and the reaction is completed to obtain a crude product reaction solution.
[0046] 3) Quench the reaction to get the crude product: slowly add 200g of absolute ethanol and 20g of deionized water to the reaction solution of the above crude product to quench the reaction...
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