IF you are looking for just a sketch, why not do it in acad? Yes, you can't import the PDF, but you could of brought in an image. Are you making this for a 1 time use and doing it for a specific size, or are you making this parametric to where you can do different sizes of the same layout? I opened you sketch and just went to pull a dimension and the top 2 sides are not even parallel, and the lower left is missing a line completely. Actually there are multiple lines not horizontal or vertical. Plus the sketch is not fully defined as there are 71 constraints needed to fully define your sketch. You may want to re-evaluate the sketch and clean it up as the DXF will not have straight lines, unless that doesn't matter.
Please see attached for a quick variation of your part (2024)
Autodesk Certified Professional