1394389-40-2

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• 1394389-39-9 C₂₂⁽¹¹⁾CH₂₇NO₃ 

Relevant academic research and scientific papers

11C-Carbonylation through in Situ Generated 11C-Benzoyl Chlorides with Tetrabutylammonium Chloride as Chloride Source

Aromatic 11C-containing acids, amides, esters, and aldehydes were obtained through a novel 11C-carbonylative reaction. In the two-step process, aryl iodides are first reacted with 11CO and tetrabutylammonium chloride in a palladium-mediated reaction to yield 11C-benzoyl chlorides in situ. The crude mixture is then further treated with either a hydroxide, amine, alcohol, or a hydride in a second vial to furnish the final 11C-carbonyl product. The monodentate ligand tri-tert-butylphosphonium tetrafluoroborate was proven to be crucial for obtaining high radiochemical yields (RCY). A wide range of 11C-containing carbonyl compounds were successfully radiolabeled in moderate to excellent RCYs, ranging from 41–93 %. The synthetic retinoic acid tamibarotene was obtained in a RCY of 89 %, whereas the Boc-protected procainamide was labelled in 68 % RCY, which is a significantly increase (2–3 fold) in RCY compared to other published methods.

Palladium-mediated 11C-carbonylations using aryl halides and cyanamide

A robust and high-yielding radiochemical synthesis of 11C-N-cyanobenzamides using a palladium-mediated aminocarbonylation with 11C-CO, aryl halides and cyanamide is described. The bidentate ligand 1,1′-bis(diphenylphosphino)ferrocene provided 11C-N-cyanobenzamides from aryl-iodides, bromides, triflates and even chlorides in 28-79% radiochemical yield after semi-preparative HPLC. To further highlight the utility of this method, novel 11C-N-cyanobenzamide analogs of flufenamic acid, meflanamic acid, dazoxiben and tamibarotene were synthesized in 34-71% radiochemical yields.

Synthesis of [11C]Am80 via novel Pd(0)-mediated rapid [ 11C]carbonylation using arylboronate and [11C]Carbon Monoxide

11C-labeled methylbenzoates [11C]4a-d were synthesized using Pd(0)-mediated rapid cross-coupling reactions employing [ 11C]carbon monoxide and arylboronic acid neopentyl glycol esters 3a-d under atmospheric pressure in methanol-dimethylformamide (MeOH-DMF), in radiochemical yields of 12 ± 5-26 ± 13% (decay-corrected based on [11C]O). The reaction conditions were highly favorable for the synthesis of [11C]Am80 ([11C]2) and [11C]methyl 4-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)carbamoyl)benzoate ([11C]2-Me) using 4-(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)-N-(5,5,8, 8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)benzamide (5), both of which produced a decay-corrected radiochemical yield (RCY) of 26 ± 13%, with >99% radiochemical purity and an average specific radioactivity of 44 GBq/μmol. The yields of [11C]4a, [11C]2-Me, and [ 11C]2 were improved by the use of a 2-fold excess of the solvents and reagents under the same conditions to give respective yields of 66 ± 8, 65 ± 7, and 48 ± 2%.

Synthesis of [11C]Am80 via novel Pd(0)-mediated rapid [ 11C]carbonylation using arylboronate and [11C]Carbon Monoxide

11C-labeled methylbenzoates [11C]4a-d were synthesized using Pd(0)-mediated rapid cross-coupling reactions employing [ 11C]carbon monoxide and arylboronic acid neopentyl glycol esters 3a-d under atmospheric pressure in methanol-dimethylformamide (MeOH-DMF), in radiochemical yields of 12 ± 5-26 ± 13% (decay-corrected based on [11C]O). The reaction conditions were highly favorable for the synthesis of [11C]Am80 ([11C]2) and [11C]methyl 4-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)carbamoyl)benzoate ([11C]2-Me) using 4-(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)-N-(5,5,8, 8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)benzamide (5), both of which produced a decay-corrected radiochemical yield (RCY) of 26 ± 13%, with >99% radiochemical purity and an average specific radioactivity of 44 GBq/μmol. The yields of [11C]4a, [11C]2-Me, and [ 11C]2 were improved by the use of a 2-fold excess of the solvents and reagents under the same conditions to give respective yields of 66 ± 8, 65 ± 7, and 48 ± 2%.