As part of my basement reno, I needed a solution for the bathroom door that swung inside a small bathroom. With the limited space, a pocket door would be ideal but would require reframing the opening.
I found a solution in the Johnson 2610F Wall Mount rail kit which converts any door into a externally mounted sliding door. I bought the 7ft version on Ebay . The longer length can be cut down with a hacksaw.
The important dimension is the door should be at least 1-1/4″ wider than the opening. I used the existing door though it is a little bit too narrow which meant the door could come off the bottom plastic guide when closed. The length of the track should be at least double the width of the door.
Installation is pretty straight forward and they have a video on youtube.
I was able to get inset handles that fit the existing knob holes and i plugged the latch hole with a cut piece of wooden broom handle. The hinge mortises I filled with cut ends of a 2×4 which was close to the hinge dimension.
Since I have fairly thick molding around the door, there was a bit of a gap between the door and the frame so I added weatherstripping to the inside frame.
For a privacy lock, I installed a sliding latch on the inside frame with the bolt extending into the door when closed. In an emergency, the door could be opened by removing the screws in the plastic guide rail at the bottom and tilting the bottom of the door out.