191937-46-9Relevant articles and documents
Transition-Metal-Free Carbon Isotope Exchange of Phenyl Acetic Acids
Audisio, Davide,Buisson, David-Alexandre,Cantat, Thibault,Del Vecchio, Antonio,Destro, Gianluca,Elmore, Charles S.,Horkka, Kaisa,Kingston, Lee,Loreau, Olivier,Schou, Magnus,Taran, Frédéric
, p. 13490 - 13495 (2020)
A transition-metal-free carbon isotope exchange procedure on phenyl acetic acids is described. Utilizing the universal precursor CO2, this protocol allows the carbon isotope to be inserted into the carboxylic acid position, with no need of precursor synthesis. This procedure enabled the labeling of 15 pharmaceuticals and was compatible with carbon isotopes [14C] and [13C]. A proof of concept with [11C] was also obtained with low molar activity valuable for distribution studies.
Direct reversible decarboxylation from stable organic acids in dimethylformamide solution
Kong, Duanyang,Moon, Patrick J.,Lui, Erica K.J.,Bsharat, Odey,Lundgren, Rylan J.
, p. 557 - 561 (2020/09/02)
Many classical and emerging methodologies in organic chemistry rely on carbon dioxide (CO2) extrusion to generate reactive intermediates for bond-forming events. Synthetic reactions that involve the microscopic reverse-the carboxylation of reactive intermediates-have conventionally been undertaken using very different conditions. We report that chemically stable C(sp3) carboxylates, such as arylacetic acids and malonate half-esters, undergo uncatalyzed reversible decarboxylation in dimethylformamide solution. Decarboxylation-carboxylation occurs with substrates resistant to protodecarboxylation by Br?nsted acids under otherwise identical conditions. Isotopically labeled carboxylic acids can be prepared in high chemical and isotopic yield by simply supplying an atmosphere of 13CO2 to carboxylate salts in polar aprotic solvents. An understanding of carboxylate reactivity in solution enables conditions for the trapping of aldehydes, ketones, and a,b-unsaturated esters.
Preparation of 1-0-acylglucuronides of 13C-labelled (R)- and (S)-ketoprofens
Akira, Kazuki,Taira, Tadaaki,Hasegawa, Hiroshi,Shinohara, Yoshihiko
, p. 353 - 361 (2007/10/03)
The preparation of enantiomeric [1-13C]ketoprofens (KPs) and their acylglucuronides has been reported for the nuclear magnetic resonance (NMR) spectroscopic studies on the stereoselective pharmacokinetics and reactivities of KP acylglucuronides. The racemic [1-13]KP was prepared by a three-step synthetic scheme from [13C]potassium cyanide in overall yield of 23 %. The racemate was optically resolved by the formation of diastereomeric amides with (R)-(+)-α-phenylethylamine, separation of the amides by column chromatography on silica gel, and nonhydrolytic cleavage of the amide bond using nitrogen tetroxide. The yields of KP enantiomers were 30 % based on the racemate. The acylglucuronides of (R)- and (S)-[1-13C]KP were isolated from human urine after dosing of each labelled KP (100 mg) using preparative high-performance liquid chromatography following Sep-Pak C18 pretreatments. The yields of the conjugates from 0-4 h post-dose urine were roughly 50 mg.
