Is that note with connection with financing the property you sold?
Or you loaned the money to someone?
You will report selling the promissory note as selling the asset.
The question is what is your tax basis in the promissory note?
The IRS provides that the basis of property transferred to you or transferred in trust for your benefit by your spouse (or former spouse if the transfer is incident to divorce), is the same as your spouse's adjusted basis.
So you need to identify the original basis of the note. If the basis is the face value of the note - the answer is yes - you may report a capital loss.