Preparation and Potential Applications of Evacuated Closed-Cell Plastic Foams

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67368/2/10.1177_0021955X9002600201.pd

Aqueous carbonic acid: A readily removable electrolyte for the recovery of [18F]fluoride from anion exchange resins

[18F]Fluoride was recovered from [18O]target water in high yield by trapping it on a microcolumn of an anion exchange resin (20 mg Dowex 1 x 8, 400 mesh) and subsequent elution of the column (in the reverse direction) by aqueous carbonic acid at 52 atm. The carbonic acid was removed from the [18F]fluoride solution by brief heating at 85[deg]C, 1 atm. Thus no extraneous electrolyte was introduced by the extraction process. The resulting bicarbonate form of the resin was immediately capable of trapping further [18F]fluoride, permitting a repetitive remote system for recovery of [18O]water. Chloride was substantially retained on the column permitting separation of [18F]fluoride from the former.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29616/1/0000705.pd

A simple synthesis of [11C]methyl triflate

[11C]Methyl triflate ([11C]methyl trifluoromethanesulfonate) was formed in high yield when [11C]methyl iodide in a nitrogen carrier was passed at 200[deg]C through a column containing graphitized carbon impregnated with 50% by weight of silver triflate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29777/1/0000116.pd

Ion exchange reaction of [18F]fluoride with an oxidized carbon surface

[18F]Fluoride was trapped from [18O]water in high yield by ion exchange on a microporous carbon prepared by controlled oxidation to produce a cationic surface with an exchange capacity of about 350 [mu] equiv/g. The [18F]fluoride could be recovered by displacement with aqueous K2CO3. The cationic carbon offered a dimensionally rigid matrix of high thermal stability. It was characterized with respect to chemical reactivity and selectivity for anion exchange.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29626/1/0000715.pd

Rapid and efficient preparation of free amino acids from strong acid salts on columns of crosslinked poly-4-vinylpyridine

Acidic and neutral amino acids were recovered from their strong acid salts or from large excesses of strong acids by passage through columns of crosslinked poly-4-vinylpyridine. Basic amino acids eluted as the monoacid salts. High recoveries were possible with submicromolar samples.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23981/1/0000230.pd

Rapid reductive-carboxylation of secondary amines, one pot synthesis of N'-(4-11C-methyl)imipramine

A new rapid high yield synthesis of radiolabeled N'-(4-11C-methyl)imipramine has been developed using a reductive-carboxylation approach, in which 11CO2 is reacted with either N'-trimethylsilyldesimipramine or N'-lithium derivative of desimipramine, followed by lithium aluminum hydride reduction, to give no carrier added or carrier added 11C-labeled imipramine respectively. The final product is characterized by chromatographic and spectroscopic methods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26413/1/0000500.pd

A captive solvent method for rapid radiosynthesis: Application to the synthesis of [1-11C]palmitic acid

A method is described for the synthesis of [1-11C]palmitic acid,in which 11CO2 is reacted with a Grignard reagent trapped within the pores of microporous polypropylene powder in a column. The free acid is liberated by passing gaseous HCl through the column. The apparatus is very simple, facilitating automation and miniaturization of the synthesis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25612/1/0000160.pd

Tritium labeling of potential lipophilic myelin probes

Two potential lipophilic myelin imaging agents (1,1,2,2‐tetrafluoro‐1,2‐diphenylethane and 1‐fluoroadamantane) were tritium labeled. The most effective method employed the microwave discharge activation of tritium gas technique and resulted in specific activities of 177 mCi/mmol for 1,1,2,2‐tetrafluoro‐1,2‐diphenylethane and 593 mCi/mmol for 1‐fluoroadamantane. Using this tritiation method significant amounts of tritium‐for‐fluorine substitution was also observed in the labeling of 1‐fluoroadamatane, resulting in nearly equivalent amounts of tritiated adamantane and fluoroadamantane.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90398/1/2580210110_ftp.pd

Routine synthesis of N-[11C-methyl]scopolamine by phosphite mediated reductive methylation with [11C]formaldehyde

A synthesis of [11C]scopolamine capable of clinical delivery of this agent in high specific activity is described. The precursor [11C]formaldehyde was produced by catalytic oxidation of [11C]CH3OH over metallic silver and was used to N-11C-methylate norscopolamine using aqueous neutral potassium phosphite as the reducing agent. The labeling reaction was complete after 5 min at 75-80[deg]C and the [11C]scopolamine (99% radiochemical purity) was isolated by preparative HPLC. Total synthesis time is less than 45 min. Decay corrected radiochemical yields from [11C]CO2 are presently 20-43%.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27552/1/0000596.pd

Extraction of [18F]fluoride from [18O]water by a fast fibrous anion exchange resin

[18F]Fluoride for nucleophilic radiofluorination was recovered from target water by trapping on a fibrous anion exchange resin in the hydroxide form and subsequent displacement into wet methanolic K2CO3. Extraction into methanol facilitated rapid evaporation and resolubilization of the [18F]fluoride as an ion pair. The resin was first dried in situ and rehydrated with [18O]H2O to avoid isotopic dilution of the target water.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28900/1/0000737.pd