There is currently no water access in my basement. I recently purchased a double laundry tub for which I need to establish a drain line. The attached picture shows one of the main house drains descending from the first floor. I can cut in a wye into the vertical portion of the drain just above the basement floor and then connect to the laundry tub. I may have to raise the laundry tub so that I have an adequate drainage flow. But, my questions are: 1) Are there any problems that I should be aware of in attaching a new drain line in this location? 2) Would the water in the P-Trap to be placed under the laundry tub be siphoned out by the water running down the vertical drain? Any and all responses are greatly appreciated.

You should be able to cut in a 3x2 San-tee just above the 3" 45 coming out of the floor and install a 2" drain, 1-1/2" trap arm and 1-1/2 vent with an AAV without any problems whatsoever.