Reaction #1929081

Reaction equation

hydrochloric acid

compound

Methyl 4,4-difluoro-1-{[(4′-fluoro-4-methylbiphenyl-3-yl)acetyl]amino}cyclohexanecarboxylate

DMA

DMA

potassium tert-butoxide

→

title compound

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

Solvents

water

Conditions

Workup

1. 1
   Filtrationthe resulting residue was filtered off with suction
2. 2
   OtherPurification by flash column chromatography (silica gel; ethyl acetate/n-hexane 1:1)

Procedure

2.80 g (5.94 mmol) of the compound from Example 7A were initially charged in a solution of 8 ml of DMA (N,N-dimethylacetamide), a solution of 5 ml of DMA and 1.75 g (2.5 eq.) of potassium tert-butoxide was added dropwise at 20° C. and the mixture was stirred at room temperature for 4 h. The mixture was poured into 200 ml of water and the reaction was adjusted to pH 2 using concentrated aqueous hydrochloric acid, and the resulting residue was filtered off with suction. Purification by flash column chromatography (silica gel; ethyl acetate/n-hexane 1:1) gave 1.07 g (44% of theory) of the title compound.

Source