That depends on the kinds of paint that are in your jar, and on your wall.

Latex paint can be painted over with latex paint. Better not put a stronger paint (acrylics) over latex paint.
If your wall was painted with acrylics or oil based paint, you can use the primer.

Bye, Evelien

I will have to offer a differing opinion to the previous answer.

I will recommend against using a finish as a primer. Primers are designed to adhere to a wide variety of surfaces. Finish paints should be applied to non-slick surfaces.