32247-96-4

light yellow liquid

3,5-Bis(trifluoromethyl)benzyl bromide is used as derivatization reagent in detection of uracil in DNA by GC and negative chemical ionization mass spectrometry in enantioselective synthesis of non-peptidic neurokinin NK1 receptor antagonist.

Synthesis of 3, 5-bis (trifluoromethyl)-benzyl bromide:
In a 4-neck flask with capacity 1000 ml equipped with mechanical agitator, thermometer, bubble condenser and 100 ml loading funnel, 262.2 g of the product of Example 1 (ii) at 92. 8% (0. 988 moles), 550,2 g HBr 48% (3.2645 moles) are loaded; this is heated at 50°C so as to melt the alcohol, then one starts to dose 113 g of concentrated His04 (1.153 moles). Pouring is accomplished in 30 minutes, noting an increase of the internal temperature. This is heated to 100-105°C and left to react for 8 hours. The reaction is completed by reflux heating for per 1.5 hours. the mixture is left to settle and the phases are separated; the solvents are removed from the organic phase and the product in the title is obtained with a yield of 99.1 %.

[1] Patent: WO2005/35472, 2005, A1. Location in patent: Page/Page column 7-8
[2] Advanced Synthesis and Catalysis, 2016, vol. 358, # 11, p. 1731 - 1735