There are a few options to discourage inappropriate scratching.
First, try getting your cat to scratch appropriately. Start by putting a scratching post where the cat is scratching. To encourage your cat to use the scratching post, scratch on the post and call the cat over. Cats are great imitators. Praise him when he uses it and work with your cat to make it a healthy habit.
If your cat won’t use the scratching post, try sprinkling a little bit of catnip on it. Or try placing a light adhesive strip on the place you do not want your cat to scratch. This helps deter them from scratching that spot. Spraying the spot with a deterrent, such as Nature's Miracle or Just for Cats Scratching Deterrent Spray. If all else fails, you may want to try Soft Claws, which are little caps that are placed on your cat’s nails to prevent scratching.
Don’t forget to regularly clip cat’s nails. See Grooming for more information.