A method of manufacturing 2-(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)-malononitrile ([F-18]FDDNP) utilizes a semi-automated module that is used to perform fluorination, pre-purification, separation, product extraction, and formulation. The method is able to produce [F-18]FDDNP with high yields and ready for human administration under existing FDA regulations, and without the need for hazardous organic solvents such as dichloromethane (DCM), methanol (MeOH), and tetrahydrofuran (THF). The method also improves the speed with which [F-18]FDDNP can be synthesized with the method being able to generate a final product within about 90 to 100 minutes. This synthesis method is easily adaptable to FDA registered and approved automated synthesis systems.