Reaction #73581

Reaction equation

metformin hydrochloride

sodium hydroxide

→

metformin

Yield 76.9%

Solvents

ethanol

Conditions

Workup

1. 1
   Filtrationwas filtered
2. 2
   Concentrationthe filtrate was concentrated under reduced pressure
3. 3
   workup.ADDITIONThen 300 Ml of acetone was added to the resulting solid
4. 4
   FiltrationInsoluble material was filtered
5. 5
   Concentrationthe filtrate was concentrated under reduced pressure

Procedure

20.00 g (1 equivalent) of metformin hydrochloride and 4.84 g (1 equivalent) of sodium hydroxide were stirred in 200 Ml of ethanol for 2 hours at room temperature, and then remaining solid was filtered and the filtrate was concentrated under reduced pressure. Then 300 Ml of acetone was added to the resulting solid and stirred. Insoluble material was filtered, and the filtrate was concentrated under reduced pressure to obtain 12.0 g of metformin free base. 500 Ml of acetone and 10 Ml (1.45 equivalents) of glacial acetic acid were added to the metformin free base, and then the mixture was stirred. The resulting crystal was filtered and washed with acetone, and then dried at 60° C. to obtain 13.6 g of metformin acetate (yield: 59.5%).

Source