Reaktion #504982

Reaktionsgleichung

Glucosamine hydrochloride

2-acetyl-dimedone

→

crude product

Ausbeute 188.5%

2-deoxy-2-[1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)-ethylamino]-α-D-glucopyranose

Ausbeute 188.5%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe reaction mixture was stirred
2. 2
   Temperaturunder reflux for 2.5 hours
3. 3
   Temperaturthe reaction mixture was cooled to room temperature
4. 4
   Filtrationfiltered
5. 5
   SonstigeThe filtrate was evaporated
6. 6
   Waschenthe resulting solid residue was washed on a funnel with ether (3×500 mL)
7. 7
   Sonstigedried

Vorschrift

Glucosamine hydrochloride (50 g, 231 mmol) was suspended in anhydrous methanol (500 mL), then 2-acetyl-dimedone sodium salt (47.3 g, 231 mmol) was added. The reaction mixture was stirred at room temperature for 10 minutes, then 2-acetyl-dimedone (21.1 g, 115.9 mmol) was added. The reaction mixture was stirred under reflux for 2.5 hours and monitored by tlc. At the completion of the reaction (TLC: MeCN—H20, 10:2), the reaction mixture was cooled to room temperature and filtered. The filtrate was evaporated and the resulting solid residue was washed on a funnel with ether (3×500 mL) and dried to give crude product (75 g, 94%). No further purification was required for the next reaction.

Quelle