Stymied, the museum has shifted gears, asking the Empire State Development Corporation, a state agency, to condemn No. 99. The aim is to let the museum acquire the building under the laws of eminent domain, which authorize the taking of private property for a perceived greater public good — with compensation for the landlord, of course, and with any tenants relocated. The procedure is familiar. This newspaper, for example, is asking the development corporation to do the same in its behalf so it can build a new headquarters on Eighth Avenue.