Bromophenol Blue CAS 115-39-9

Bromophenol blue is colorless or light rose red fine crystals. Soluble in ethanol, benzene, ether and other organic solvents, slightly soluble in water, the aqueous solution is yellow, and blue-purple in alkaline solution. It is mainly used as an acid-base indicator, the pH discoloration range is 3.0 to 4.6, and the color changes from yellow to green to blue-violet. Dissolve phenol red in glacial acetic acid, add a solution of bromine dissolved in glacial acetic acid under stirring, pour into 60°C hot water after stirring for a few minutes, cool to room temperature, and place overnight. Filter, wash the filter cake with glacial acetic acid and benzene in turn, and air dry to obtain bromophenol blue.