Radiative decay of $\eta^{\prime}$ at CLAS

We will present preliminary experimental results of the radiative decay of $\eta^{\prime}\rightarrow\pi^{+}\pi^{-}\gamma$ based on CLAS data collected at Jefferson Lab during the photoproduction experiment $\gamma p\rightarrow p\eta^{\prime}$ for the center-of-mass energy from 1.96 to 2.72 $GeV$. The analysis is based on the highest statistics collected in this channel to date. This decay is sensitive to the box anomaly in gauge theory.