I would assume you're talking about interest paid on the mortgage on this property. Yes, you can claim the interest if the loan is secured by the property.
As for the demolition, that's between you and the lender. When you have a mortgage that is secured by the property and that property has a structure on it that is part of the deal, it's not common for the lender to allow the destruction of that which secures the loan. It can be done if you work with the lender though and they agree to your plans.
You may want to check with legal authority as far as the mortgage goes, to confirm what you can and can not do.