2-Bromo-3-bromomethylthiophene with cas registry number of 75806-84-7 is also known as 2-Bromo-3-chloro-5-(trifluoromethyl)pyridine ; Pyridine, 2-bromo-3-chloro-5-(trifluoromethyl)- ; 2-Bromo-3-chloro-5-(trifluoromethyl)pyridine 97% . It would emit acrid smoke and irritating fumes when heated to decomposition . 2-Bromo-3-bromomethylthiophene with cas registry number of 75806-84-7 is used as a pharmaceutical intermediate .