extend Baseboard heater using junction box

Hi guys, I have a question. I had my basement reconstructed after hurricane Sandy and the contractor moved my electrical cable for previously installed baseboard heater on a wall where I dont want it and the place is already sheetrocked. The wall where it was on before has been removed. I am looking to install now the baseboard heater on an adjacent wall. Originally, it's a separate cable run to sustain the necessary power for this heater . Can i use a junction box and extend that cable to another wall? Really would appreciate an answer on this.

Thanks
Ed