Exclusive single pion electroproduction off the proton in the invariant mass range up to 2 GeV and at Q2$<$5GeV2 with CLAS.

Exclusive meson electroproduction off protons is a powerful tool to probe the effective degrees of freedom in excited nucleon states at the varying distance scale where the transition from the contributions of both quark core and meson-baryon cloud to the quark core dominance. During the past decade, the CLAS collaboration has executed a broad experimental program to study the excited states of the proton using polarized electron beam and (un)polarized proton targets. The measurements covered a broad kinematic range in the invariant mass W and photon virtuality Q2 with nearly full coverage in solid angles in the hadronic CMSystem. As results, several low-lying nucleon resonance states have been explored, such as $\Delta$(1230)3/2+, N(1440)1/2+, N(1520)3/2-, and N(1535)1/2- in particular for W$<$1.6 GeV. In this talk, we present preliminary cross-sections and helicity amplitudes of the reaction g*p$\to$npi+ at higher W (1.6 to 2.0 GeV). Some of the excited states with isospin 1/2 and with masses near 1.7 GeV can be accessed in single npi+ production as there are no isospin 3/2 states present in this mass range with the same spin-parity assignments. These are the N(1675)5/2-, N(1680)5/2+, and N(1710)1/2+ states. We will briefly discuss preliminary results for these states.