Basement framing can be complex because of plumbing pipes. Framing around these pipes requires a little design skill and ingenuity for you may decide to build out the whole wall to keep from having a jog in the wall. If the plumbing pipe has a clean-out access, you must frame around it in a manner as to allow access to it after the drywall is installed. In essence, framing around plumbing pipes is simply building a box against the wall.
Draw a line on the floor parallel to the wall that's behind the pipe and far enough out to embed the plumbing pipe into the new wall. Check the top of the pipe for plumb (straight up and down) with a level. Sometimes pipes lean into the room and you must adjust the framing accordingly.
Square back to the wall and draw a line on the floor. You now have the shape of the bump out on the floor.
Install blocking, if necessary, near the top of the plumbing pipe to provide a nailer for the top of the framing that is to go around the pipe. You will nail the top plate into the backing, which should also be positioned to provide backing for the drywall screwed to the ceiling. You will also need to install a 2x4 on the back wall on each side of the pipe to provide a place to attach the new wall. Position the stud so that half of it can be a nailer for the new plumbing wall and half of it can be the nailer for the drywall that will go up to the plumbing box.
Cut the bottom plate of the new walls to go around the pipes out of treated lumber and the top plates from non-treated lumber. Cut the vertical studs to fit between the top and bottom plates and nail the plates to the studs with 16d sinkers.
Raise one wall and drill holes in the bottom plate through to the concrete. Drive in 2-1/2 inch concrete anchors. Plumb the wall and nail the top plate to the ceiling framing or the backing. Repeat this process for the other two wall segments.