Sulfuric Acid → Creatine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a 22% (w/w) unprocessed aqueous solution of 6160 g (about 12.2 mol) sodium N-methylglycinate, 20% sulfuric acid was added under stirring and cooling in an ice-salt liquor bath to adjusting the pH to 9.8. The temperature was kept below 15° C. in this process. Under the condition that the internal temperature was kept at 40° C., 3052 g (11 mol) of S-methylisothiourea sulfate was slowly added into the solution under stirring within 100 minutes. Then the solution was further stirred for 15 minutes at an internal temperature not more than 40° C. Thereafter, a hot vapor was fed into the solution for 45 minutes, and a crystal was precipitated. After staying for 7 hours, the solution was centrifuged to remove the mother liquor, then was washed with distilled water several times (80 ml each time) until pH value becomes to ≦7.6. The product was washed once with 1100 ml of 95% ethanol to obtain a crude product. 1260 ml of water was added to the crude product, and the mixture was heated to 45° C. under stirring. Then pH was adjusted to 7.0 with addition of 10% sulfuric acid. Thereafter, the temperature was raised to 80° C. Then 0.5 g of disodium EDTA was added thereto, and the temperature was raised to 90° C. After stirring for 15 minutes, the solution was filtered. The filtrate was cooled to a temperature below 20° C., and a crystal was obtained. The crystalline product was recovered by centrifugation, washed once with 50 ml of distilled water and once with 70 ml of 95% ethanol, and dried in a vacuum drier at 40° C. under 20 millibar pressure. 1044 g of the product (S-methylisothiourea was used as the standard) was obtained. The yield of creatine-monohydrate was 70.3, and the content or purity (HPLC) was 99.4%. After dehydrated at 80° C., creatine was obtained. There was substantially no product loss in this process.

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