Hello, I have a 2" drain that goes to 1 1/2" for the kitchen sink and connected dishwasher. I am tool proficient and have some plumbing experience. I want to add a washing machine drain breaking out from the 2" hub. The washing machine is 5' away on the same wall. The drain pipe need not be in the wall as most of the run has countertop cabinets. My question is how do create a tee to the (I believe threaded cast iron) and break out to a stand pipe with a ventless valve? If my terms are incorrect please forgive as I am not all that familiar with the correct names. Please advise.

You should not think along the lines of breaking but I think that was just a figure of speech. Cut the cast iron drain with a hack saw or reciprocating saw. You can install a 2" ABS or PVC wye stand pipe using a no-hub coupling. MWI 112NHC Hubless Fitting, No-Hub Coupling, 1-1/2" Diameter (2) - PlumberSurplus.com