Hydrochloric Acid → 3-(5-Bromo-2-methylphenyl)-8,8-difluoro-4-hydroxy-1-azaspiro[4.5]dec-3-en-2-one

Participants

Reaction Conditions

Reaction Steps

11.0 g (27.2 mmol) of the compound from Example 10A were initially charged in a solution of 22 ml of DMA (N,N-dimethylacetamide), a solution of 10 ml of DMA and 3.54 g (1.1 eq.) of potassium tert-butoxide was added dropwise at 20-30° C. and the mixture was stirred at 30° C. for a further 1 h. The mixture was poured into 200 ml of water and the mixture was adjusted to pH 2 using aqueous 1N hydrochloric acid, the resulting precipitate was filtered off with suction, washed with water and dried in a vacuum drying cabinet at 50° C. The product was suspended in hot methyl tert-butyl ether, n-hexane was added and the mixture was filtered off with suction and dried. This gave 11.0 g (97% of theory) of the title compound in a purity of 89%.

Provenance & Evidence