114635-99-3Relevant academic research and scientific papers
Syntheses of 2,5- and 2,6-Difluoronorepinephrine, 2,5-Difluoroepinephrine, and 2,6-Difluorophenylephrine: Effect of Disubstitution with Fluorine on Adrenergic Activity
Chen, George T.,King, Michael,Gusovsky, Fabian,Creveling, Cyrus R.,Daly, John W.,et al.
, p. 3947 - 3955 (2007/10/02)
Synthetic routes to difluorinated analogs of the adrenergic agonists, norepinephrine (NE), epinephrine (E), and phenylephrine (PE) have been developed.The syntheses were based on elaboration of the ethanolamine side chains from the appropriately polyfunctionalized benzaldehydes.The benzaldehydes were prepared from precursor difluorinated benzenes by sequential regioselective lithiations and reaction with electrophiles to introduce hydroxyl and carboxaldehyde functionalities.Binding and functional assay data demonstrate that the 2,6-difluorinated analogs are relatively inactive at both α- and β-adrenergic receptors.These results are consistent with earlier observations that 2-fluoro substitution of adrenergic agonists decreases α-adrenergic activity whereas 6-fluoro substitution decreases β-adrenergic activity.
Unexpected Regioselectivity in the Lithiation of Fluoroanisoles
Furlano, David C.,Calderon, Silvia N.,Chen, George,Kirk, Kenneth L.
, p. 3145 - 3147 (2007/10/02)
The regioselectivity of lithiation of a series of fluoroanisoles and fluoroveratroles has been studied by determining the ratio of isomeric aldehydes produced by dimethylformamide quenching.The position of lithiation is influenced by such factors as temperature and time of the reaction.Contrary to published reports, fluorine competes significantly with the methoxy group as an ortho director in lithiation reactions.Lithiation of dimethyl-tert-butylsilyl ethers of fluorophenols proceeds exclusively ortho to fluorine.
