N-bromobutanimide → N-[4-(Bromomethyl)-3-(trifluoromethyl)phenyl]-2,2,2-trifluoroacetamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 60.9 g (224.6 mmol) of N-(4-methyl-3-trifluoromethyl-phenyl)-2,2,2-trifluoro-acetamide in 830 ml n-butyl acetate under a nitrogen atmosphere, 44 g (247 mmol) N-bromosuccinimide and 830 mg (5 mmol) azo-iso-butyronitrile are added. The suspension is heated up to 60° C. and then illuminated for 30 min by a Phillips low-voltage lamp (500 W; 10500 lm), whereby the temperature rises to 70-75° C. and a clear brown solution is formed. There is still remaining educt detectable, therefore another 22 g N-bromosuccinimide are added in 3 portions. After totally 6 h illumination, the resulting solid is filtered off and discarded and the filtrate concentrated. The residue is distributed between 2 l CH2Cl2 and 1 l H2O and the aqueous layer extracted with 1 l CH2Cl2. The organic phases are washed 4 times with 1 l H2O, 0.5 l brine, dried (Na2SO4) and concentrated. Column chromatography (SiO2; hexane/CH2Cl2 2:1→1:1) and crystallization from CH2Cl2/hexane yields the title compound: m.p.: 119-120° C.

Provenance & Evidence