A Florida businessman who once factored in the Smurfs cartoon empire lost a bid Tuesday to withdraw his guilty plea in an $11 million shakedown plot targeting his financier son-in-law.

With that, Stuart R. Ross was sentenced to the five years' probation he was promised when he pleaded guilty in August to attempted grand larceny. But his lawyer said he now plans to ask an appeals court to let Ross take back the plea, which he says Ross entered while pressured by medical problems.

In his plea, Ross admitted threatening to destroy son-in-law David S. Blitzer's professional reputation if not paid $5.5 million. Ross also acknowledged offering to give up any rights to see his grandchildren for another $5.5 million.

Ross, 74, agreed to plead guilty while jailed on $200,000 bond awaiting trial. He was contending with pneumonia, cancer and other health woes that weren't getting adequate care behind bars, and he took the plea deal to gain his freedom, lawyer Matthew Myers said outside court Tuesday.

"He was under tremendous duress," Myers said. "It's the only reason why he pled."

But state Supreme Court Justice Bonnie Wittner rebuffed Ross' request to withdraw his plea. Defendants pleading guilty are routinely warned they can't revisit the decision and are asked to acknowledge they are indeed guilty.