A compound $\mathrm{A}$ $\left({\mathrm{C}}_7{\mathrm{H}}_8\mathrm{O}\right)$ is insoluble in ${\mathrm{NaHCO}}_3$ solution but dissolve in $\mathrm{NaOH}$ and give a characteristic colour with neutral ${\mathrm{FeCl}}_3$ solution. When treated with Bromine water compound $\mathrm{A}$ forms the compound $\mathrm{B}$ with the formula ${\mathrm{C}}_7{\mathrm{H}}_5{\mathrm{OBr}}_3.$ $\mathrm{A}$ is