Réaction #986756

Équation de réaction

1-bromo-3,5-dimethyl adamantane

urea

hydrochloric acid

→

1-amino-3,5-dimethyl adamantane

Solvants

formic acid

Conditions de réaction

Traitement

1. 1
   TempératureCooling to the room temperature
2. 2
   workup.WAITto hydrolyze at 100° C. for about 1 hour
3. 3
   ExtractionAdjusting with 30% sodium hydroxide solution to a pH of 12, extracting with butyl acetate twice
4. 4
   Lavagewashing with water
5. 5
   ConcentrationConcentrating under reduced pressure

Mode opératoire

To 100 g of 1-bromo-3,5-dimethyl adamantane and 86 g of urea, adding 72 ml of 94 wt % formic acid, heating to 120° C. and holding for 2 hours. Cooling to the room temperature and adding 385 ml of 10% hydrochloric acid to hydrolyze at 100° C. for about 1 hour. Adjusting with 30% sodium hydroxide solution to a pH of 12, extracting with butyl acetate twice, combining the organic layers and washing with water. Concentrating under reduced pressure to yield a limpid yellow solution as 1-amino-3,5-dimethyl adamantane crude. To the crude, adding 150 ml of ethanol and concentrated hydrochloric acid, heating to dissolve and crystallizing to yield white solid. Drying the solid and re-crystallizing with water to yield 60.4 g of pure Memantine Hydrochloride. The yield is 68.1% (GC 99.1%).

Source