San Diego-based Somaxon Pharmaceuticals, a specialty pharmaceuticals firm working on insomnia on other drugs, said today that it has raised $5M in a private placement. The firm said it raised the $5M from Paladin Labs, Inc., and comes in conjunction with an exclusive collaboration deal with Paladin. Paladin is commercializing Somaxon's Silenor compound for treating insomnia in Canada, South America, and Africa.