Microwave-assisted One-pot Synthesis of N-succinimidyl-4-[¹⁸F]fluorobenzoate ([¹⁸F]SFB)

This procedure will demonstrate a novel microwave assisted one pot synthesis of F 18 SFB based on a three step radio chemical process with an anhydrous D protection step. The process begins with the radio Fluor nation of Ethel four NNN Trimethyl ammonium benzoate tri fate under microwave heating in the presence of dried fluoride and DMSO to afford Ethel four F 18 fluoro benzoate. In the next step, addition of A-D-M-S-O solution of potassium turt oxide followed by microwave radiation, complete C anhydrous D protection and yields potassium four F 18 Flora benzoate.

The final conversion into crude F 18 SFB is achieved using TSTU activation. TSTU in aceto nitrile is added to the reaction mixture containing the four F 18 flu, benzoate, salt, and heated. The last step of the procedure is to purify the crude F 18 SFP by solid phase extraction and high performance liquid chromatography.

Ultimately, results can be obtained that show novel one pot simplified and rapid F 18 SFB synthesis can be accomplished through anhydrous D protection and microwave heating. Individual new to the SFB synthesis. My struggle because it require complicated reaction set up and numerous of purification and drying steps due to the use of EQU solution my postoc dr.

Were demonstrate a procedure for us Prior to the start of this protocol. Set up the apparatus for microwave assisted one pot F 18 SFP synthesis as described in the written protocol. Once the apparatus is set up, start the HPLC to precondition the HPLC column.

Dilute F 18 fluoride solution in oh 18 water with a mixture of crypto fix 2 22 1 molar aqueous potassium carbonate and aceto nitrile, and then transfer to RV one. Execute the drying sequence under the microwave control program to remove residual water in RV one after cooling down. When the system temperature is below 50 degrees Celsius, add an additional one milliliter of aceto nitrile to the reactor and repeat the sequence one more time to synthesize Ethel four 18 F FLUA benzoate.

First, add A-D-M-S-O solution containing Ethel four NNN trimethyl ammonium benzoate tri into RV one via inlet line two. Then execute the labeling sequence under the microwave control program with stirring vessel cooling and all valves closed. Next, synthesize potassium for F 18 fluoro benzoate by adding 0.5 milliliters of DMSO solution containing potassium turt oxide into RV one via inlet Line three.

Execute the D protect program under the microwave control program with stirring vessel cooling and all valves closed. Finally synthesize the crude F 18 SFB by adding aceto nitrile solution containing TSTU to RV one via inlet Line six. Execute the coupling sequence under the microwave control program with stirring vessel cooling and all valves closed to afford the crude F 18 SFB product.

Begin preparation of SPE purified F 18 SFB by adding one milliliter 5%aqueous acetic acid to RV one via inlet line seven to neutralize the reaction mixture. Then transfer the solution into vial B containing eight milliliters of 5%aqueous acetic acid. Pass the diluted reaction mixture through an SPE cartridge to trap crude F 18 SFP using nitrogen at 10 pounds per square inch.

Once passed through. Wash the SPE cartridge with a mixture of aceto, nitrile and water from reservoir A elute the F 18 SFB into RV two. Using two milliliters of aceto nitrile from reservoir C, dilute the SPE purified F 18 SFB with two milliliters of water in RV two and transfer the mixture into the five milliliter HPLC loop.

Inject the solution into radio HPLC. The fraction containing purified F 18 SFB should appear at a retention time of about eight to 10 minutes. Collect the sample into vial D, which is prefilled with 10 milliliters of water.

It is critical that the fraction volume collected here is for to five milliliters. Pass the diluted reaction mixture from vial D through a second SPE cartridge to trap the purified F 18 SFB using nitrogen 10 pounds per square inch. After the mixture is passed through, dry the cartridge with a stream of nitrogen for two to three minutes.

Elute the purified F 18 SFB in into RV three. Using three milliliters of ether from reservoir E.Finally evaporate the solvent in RV three to dryness by a gentle stream of nitrogen gas using a water bath warm to 40 degrees Celsius. The final dried F 18 SFB can be reconstituted into PBS buffer for the downstream application.

The identity of final F 18 SFB product was confirmed by comparison of HPLC retention time with a non-radioactive SFB reference. The purified F 18 SFB was also analyzed through radio TLC and HPLC to determine its radio, chemical and chemical purity. The radio chemical yield of F 18 SFP was 35 plus minus 5%within 60 minutes after HPLC purification with high radio chemical purity and good chemical purity.

The specific activity was 1.8 to nine curie per micromole depending on the starting radioactivity. Don't forget working with radiation and radioactive materials can be extremely hazardous and precautions such as shooting and personal dosimeter and remote controllable instruments should be taken all the time while performing this procedure.