Sodium Hydroxide → 4-Chloro-2-fluoro-5-(2,2-difluorocyclopropylmethoxy)phenylhydrazine

Participants

Reaction Conditions

Reaction Steps

29.3 g 4-Chloro-2-fluoro-5-(2,2-difluorocyclopropylmethoxy)aniline was treated first with 45 ml half concentrated hydrochloric acid and then with 273 ml concentrated hydrochloric acid. It was then cooled to -10° C. and treated dropwise with a solution of 8.3 g sodium nitrite in 17 ml water at a such rate that the temperature of the reaction mixture did not rise above -5° C. It was stirred for 3 hours at -5° C. and the at -15° C., a solution of tin (II) chloride dihydrate in 34 ml concentrated hydrochloric acid added dropwise at such a rate that the temperature of the reaction mixture did not exceed -10° C. It was warmed at room temperature overnight. For the work-up, it was cooled to 0° C. and slowly neutralised with with 430 ml 32% caustic soda solution. The precipitated tin hydroxide slurry was separated by filtration through Celite and the filter cake washed with ether and the aqueous mother liquor extracted with ether. The combined organic phases were dried over magnesium sulphate and the solvent removed.

Provenance & Evidence