How to fit 2 inch plastic pipe to 9 inch cast iron sewer pipe?

I currently have an old 9 inch cast iron sewer pipe in my basement which a cast iron inlet spout is moulded onto to. This inlet pipe is only about 1 inch internal diameter which means it cloggs up easily. I want to drill a 2 inch hole and connect a plastic pipe. Does anyone know of an attachment that I can use.