Reaction #1929080

Reaction equation

potassium tert-butoxide

compound

Methyl 1-{[(4′-chloro-4-methylbiphenyl-3-yl)acetyl]amino}-4,4-difluorocyclohexanecarboxylate

hydrogen chloride

→

3-(4′-Chloro-4-methylbiphenyl-3-yl)-8,8-difluoro-4-hydroxy-1-azaspiro[4.5]dec-3-en-2-one

Solvents

N,N-dimethylacetamide

N,N-dimethylacetamide

Conditions

Workup

1. 1
   workup.ADDITIONwas added dropwise until a pH of 2
2. 2
   Filtrationthe precipitate was filtered off with suction
3. 3
   Washwashed with water
4. 4
   OtherFor further purification
5. 5
   Extractionextracted with 50 ml of 1N aqueous sodium hydroxide solution
6. 6
   Filtrationfiltered off with suction
7. 7
   Washwashed with water and, for purification
8. 8
   Othersuspended in 25 ml of hot acetonitrile on an ultrasonic bath
9. 9
   Filtrationfiltered off with suction
10. 10
    Washwashed
11. 11
    Otherdried

Procedure

Under argon and at 20 to 30° C., 3.31 g (28.0 mmol) of potassium tert-butoxide in 10 ml of N,N-dimethylacetamide were added to 11.1 g (25.5 mmol) of the compound from Example 6A in 22 ml of N,N-dimethylacetamide. The reaction mixture was stirred at 30° C. for 3 h. The reaction mixture was then added to 250 ml of ice-water, 1N aqueous hydrogen chloride solution was added dropwise until a pH of 2 had been reached and the precipitate was filtered off with suction and washed with water. For further purification, the product was taken up in methylene chloride and extracted with 50 ml of 1N aqueous sodium hydroxide solution, the aqueous phase was acidified with aqueous 1 N hydrochloric acid, filtered off with suction, washed with water and, for purification, suspended in 25 ml of hot acetonitrile on an ultrasonic bath, filtered off with suction, washed and dried. This gave 5.70 g (55% of theory) of the title compound.

Source