A method for preparing p-thiocresol-tetra-o-acetyl-β-d-galactose
A technology of thiocresol and acetyl group is applied in the field of preparation of p-thiocresol-tetra-O-acetyl-β-D-galactose, and can solve the problems of complicated operation, unpleasant smell, low synthesis rate, etc. problem, to achieve the effect of simple operation, improved yield and easy crystallization
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Embodiment 1
[0025] a. Separately cool 400ml acetone, 80g p-thiocresol and 100g bromo-tetra-O-acetyl-β-D-galactose to 0°C, dissolve p-thiocresol and bromo-cresol with 0°C acetone Tetra-O-acetyl-β-D-galactose and then mixed and stirred;
[0026] b. Add an alkaline aqueous solution of sodium hydroxide with a mass concentration of 20%, adjust the pH of the solution to 6, keep the temperature at 3°C, and stir for 60 minutes;
[0027] c. After the reaction is completed, dilute hydrochloric acid is added to neutralize the solution to pH=7.2;
[0028] d. Slowly add water at 40°C under stirring at -5°C until crystals are formed, stop adding water, continue stirring for 1 hour, centrifuge, and wash the crystals with a mixed solution of acetone and water with a volume ratio of 1:1;
[0029] e. After drying, crystals are obtained.
[0030] The quality of the crystal obtained by weighing in the present invention is 98.3g, and the calculated yield is 91.38%;
[0031] The present invention carries ou...
Embodiment 2
[0034] a. Separately cool 450ml acetone, 90g p-thiocresol and 100g bromo-tetra-O-acetyl-β-D-galactose to 5°C, dissolve p-thiocresol and bromo-cresol with 5°C acetone Tetra-O-acetyl-β-D-galactose and then mixed and stirred;
[0035] b. Add an alkaline aqueous solution of sodium hydroxide with a mass concentration of 30%, adjust the pH of the solution to 6.5, keep the temperature at 10°C, and stir for 30 minutes;
[0036] c. After the reaction is completed, dilute hydrochloric acid is added to neutralize the solution to pH=7.8;
[0037] d. Slowly add water at 58°C dropwise under stirring at 0°C until crystals are formed, stop adding water, continue stirring for 3 hours, centrifuge, and wash the crystals with a mixed solution of acetone and water with a volume ratio of 1:2;
[0038] e. After drying, crystals are obtained.
[0039] The quality of the crystal obtained by weighing in the present invention is 99.45g, and the calculated yield is 92.45%;
[0040] In the present inve...
Embodiment 3
[0043] a. Separately cool 500ml acetone, 110g p-thiocresol and 100g bromo-tetra-O-acetyl-β-D-galactose to 3°C, dissolve p-thiocresol and bromo-cresol with 3°C acetone Tetra-O-acetyl-β-D-galactose and then mixed and stirred;
[0044] b. Add an alkaline aqueous solution of sodium hydroxide with a mass concentration of 15%, adjust the pH of the solution to 6.8, keep the temperature at 5°C, and stir for 50 minutes;
[0045] c. After the reaction is completed, dilute hydrochloric acid is added to neutralize the solution to pH=7.5;
[0046] d. Under stirring, slowly add water at 52°C dropwise at 5°C until crystals are formed, stop adding water, continue stirring for 2 hours, centrifuge, and wash the crystals with a mixed solution of acetone and water with a volume ratio of 1:1;
[0047] e. After drying, crystals are obtained.
[0048] The quality of the crystal obtained by weighing in the present invention is 103.65g, and the calculated yield is 96.36%;
[0049] In the present in...
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