Rolling over profits in one property to avoid tax
I'm under contract on an existing single family in Billings, Montana. I already own an existing multiplex here in Billings (and apparently that property is like finding unicorn farts). My question is, if I wanted to flip the property I'm under contract on to pay down the mtg on my quad, would I be able to avoid taxation on those profits from the flip? Can you roll profits from one property sale into an already-existing property within a year and thus avoid cap gains? We may try and BRRR the property alternatively too...any thoughts?