Hydrochloric Acid → (3R,4R,5S,6R)-3-amino-6-(hydroxymethyl)oxane-2,4,5-triol hydrochloride

Participants

Reaction Conditions

Reaction Steps

The apparatus for this test consisted of a 1 liter round bottom vessel heated with a heating mantel. The ingredients, 150 grams of water, 21 g of 98% N-acetylglucosamine and 238 grams of 36.7% hydrochloric acid, were mixed together and added to the reaction vessel. The stirred reaction mix was heated up to 70° C. and mixed for 3 hours at which time the mixture was transferred to a beaker and cooled to 20° C. Few crystals were present. The mixture was transferred back into the reaction vessel and 10 grams of N-acetylglucosamine added. The reactor was reheated to 70° C. and reacted for 3 hours, cooled to 4° C. overnight. The crystals present were filtered and washed with ethanol, vacuum dried and assayed (20 g of glucosamine hydrochloride at 99.9%). The filtrate was transferred back into the reaction vessel and 10 g of N-acetylglucosamine were added. The reactor was again heated to 70° C., reacted for 3 hours, cooled overnight to 4° C., filtered, ethanol washed, vacuum dried and assayed (16.1 g of glucosamine hydrochloride at 99.6%). The filtrate was again returned to the reactor, 41.5 grams added and the reaction cycle repeated. Thirty-three grams of glucosamine hydrochloride resulted from the 4th cycle with an assay of 99.5%. The total yield was 86% with all the glucosamine hydrochloride produced 99+in assay and white in color. This material did not need recrystallization.

Provenance & Evidence