Measurement of Branching Fractions of $psi(3686)rightarrowphieta^prime, phi f_1(1285)$ and $phi eta(1405)$

Using a sample of $448.1times10^6$ $psi(3686)$ events collected with the BESIII detector, we perform a study of the decay $psi(3686) rightarrow phi pi^{+}pi^{-}eta$. The branching fraction of $psi(3686)rightarrowphieta^prime$ is determined to be $(1.51pm0.16pm0.12)times 10^{-5}$, which is consistent with the previous measurement but with significantly improved precision. The resonances $f_{1}(1285)$ and $eta(1405)$ are clearly observed in the $pi^{+}pi^{-}eta$ mass spectrum with statistical significances of $18sigma$ and $9.7sigma$, respectively. The corresponding product branching fractions are measured to be $mathcal{B}(psi(3686)rightarrowphi f_{1}(1285),f_{1}(1285)rightarrowpi^{+}pi^{-}eta) =(1.03pm0.10pm0.09)times 10^{-5}$ and $mathcal{B}(psi(3686)rightarrowphieta(1405),eta(1405)rightarrowpi^{+}pi^{-}eta) =(8.46pm1.37pm0.92)times 10^{-6}$.