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[摘要]：C-11-labeled methylbenzoates [C-11]4a-d were synthesized using Pd(0)-mediated rapid cross-coupling reactions employing [C-11] 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 [C-11]O). The reaction conditions were highly favorable for the synthesis of [C-11]Am80 ([C-11]2) and [C-11]methyl 4-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)carbamoyl)benzoate ([C-11]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/mu mol. The yields of [C-11]4a, [C-11]2-Me, and [C-11]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%. |
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