Method for converting N-acetylneuraminic acid hydrate into N-acetylneuraminic acid

[0016] Example 1:

[0017] The method for converting N-acetylneuraminic acid hydrate into N-acetylneuraminic acid in this embodiment is as follows:

[0018] 1. Select N-acetylneuraminic acid dihydrate as raw material, and the purity of N-acetylneuraminic acid dihydrate is 98.1%;

[0019] 2. Weigh 10g of the above-mentioned N-acetylneuraminic acid dihydrate and add a certain amount of purified water to prepare an aqueous solution of N-acetylneuraminic acid dihydrate with a concentration of 30g / L;

[0020] 3. Put the N-acetylneuraminic acid dihydrate aqueous solution prepared in step 2 into a drying box, vacuum to -0.1MPa, and heat to 50°C to evaporate the water in the aqueous solution, and finally dry the material. The dried material was tested to be N-acetylneuraminic acid and the content was 98.0%. Crystals after drying (appearance like figure 1 Shown) Detected by high performance liquid chromatography (results are as figure 2 Shown).

[0021] Example 2:

[0022] In this embodiment, the method for converting N-acetylneuraminic acid hydrate into N-acetylneuraminic acid is as follows:

[0023] 1. Select N-acetylneuraminic acid dihydrate as raw material, and the purity of N-acetylneuraminic acid dihydrate is 98.5%;

[0024] 2. Weigh 10g of the above-mentioned N-acetylneuraminic acid dihydrate and add a certain amount of purified water to prepare an aqueous solution of N-acetylneuraminic acid dihydrate with a concentration of 40g / L;

[0025] 3. Put the N-acetylneuraminic acid dihydrate aqueous solution prepared in step 2 into a drying box, vacuum to -0.1MPa, and heat to 60°C to evaporate the water in the aqueous solution, and finally dry the material. The dried material was tested to be N-acetylneuraminic acid and the content was 98.5%.

[0026] Example 3:

[0027] The method for converting N-acetylneuraminic acid hydrate into N-acetylneuraminic acid in this embodiment is as follows:

[0028] 1. Select N-acetylneuraminic acid dihydrate as the raw material, and the purity of N-acetylneuraminic acid dihydrate is 99.1%;

[0029] 2. Weigh 10g of the above-mentioned N-acetylneuraminic acid dihydrate and add a certain amount of purified water to prepare an aqueous solution of N-acetylneuraminic acid dihydrate with a concentration of 50g / L;

[0030] 3. Put the N-acetylneuraminic acid dihydrate aqueous solution prepared in step 2 into a drying box, vacuum to -0.1MPa, and heat to 70°C to evaporate the water in the aqueous solution, and finally dry the material. The dried material was tested to be N-acetylneuraminic acid and the content was 99.0%.