I am looking to put a 1/2 bathroom is my basement. There is already a 4in drain pipe in the concrete floor. Right now my washing machine drains into it. Can I use that drain pipe for a toilet?

I am looking to put a 1/2 bathroom is my basement. There is already a 4in drain pipe in the concrete floor. Right now my washing machine drains into it. Can I use that drain pipe for a toilet?
No! What you could do is remove the 4" floor drain and connect the toilet to the pipe. Your lavatory will connect to the 4" pipe with a 4 X 2" wye or combination wye and eighth bend and wet vent the toilet. You must a vent run out from the lavatory to the roof or revent back in the attic to a existing dry vent. If local codes permit you may vent your group with a AAV,( Air Admittance Vent) instead of running a vent out the roof. Good luck, Tom