Synthesis of saturated fatty acids 11C(13C)-labelled in the ω-methyl position

Abstract

A method for the preparation of saturated fatty acids 11C (13C)‐labelled in the ω‐methyl position is described. A highly reactive zerovalent copper complex was prepared from lithium naphtalenide reduced lithium(2‐thienyl)iodocuprate. The labelling precursors were obtained by addition of tert‐butyl ω‐iodocarboxylates to the organocuprate and these were reacted with [11C]methyl iodide to form 11C‐labelled, protected intermediates. The tert‐butyl ester protecting group was rapidly removed with trifluoroacetic acid, affording fatty acids 11C‐labelled in the ω‐methyl position. A solid phase extraction method was developed and preceded final HPLC purification. In a typical run starting with 2.75 GBq of [11C]methyl iodide, 375 MBq (66%) [16‐11C]palmitic acid was obtained within 46 min from the end of the radionuclide production. © 1997 John Wiley & Sons, Ltd.

Radical Coupling of Iodocarbonyl Compounds with Butenylindium Generated by Transmetalation between Cyclopropylmethylstannane and Indium Halides

“…All iodocarobnyls 2a − l were prepared according to the known method . The spectral data of 2d , 2e , 2g , 2h , 2i , 2k , and 2l were in excellent agreement with the reported data. The spectral data of 2c were in an excellent agreement with those obtained for the commercially available product.…”

Improved Methods for the Synthesis of [ω-11C]Palmitic Acid

“…Previous methods for the synthesis of [ω- 11 C]palmitic acid ( 1 ) via incorporation of [ 11 C]CH 3 I possess various drawbacks. ,, For example, a previous approach from this laboratory involves the tedious preparation of a precursor Grignard reagent that produces large amounts (ca. 60 mg) of unlabeled nor-acid and utilizes a harsh RuO 4 oxidation that generates a number of byproducts …”

Whole-body pharmacokinetics of HDAC inhibitor drugs, butyric acid, valproic acid and 4-phenylbutyric acid measured with carbon-11 labeled analogs by PET

“…Such studies may provide insight into the involvement of epigenetic processes and other mechanisms in their therapeutic actions and side effects. In this article, we describe the radiosynthesis and PET imaging studies of [ 11 C]BA [35], [ 11 C]PBA and [ 11 C]VPA. Each acid was radiolabeled with carbon-11 by reaction of the respective Grignard reagent with 11 CO 2 and then purified by semi-preparative HPLC.…”