One-loop pentagon integral with one offshell leg in $d$ dimensions from differential equations in $ϵ$-form

We apply differential equations technique to the calculation of the one-loop massless diagram with one offshell legs. Using reduction to $ϵ$-form, we managed to obtain a simple one-fold integral representation exact in space-time dimensionality. Expansion of the obtained result in $ϵ$ and analytical continuation to physical region are discussed.