30012-51-2Relevant articles and documents
Selective Mono-methylation of Arylacetonitriles and Methyl Arylacetates by Dimethyl Carbonate
Selva, Maurizio,Marques, Carlos Alberto,Tundo, Pietro
, p. 1323 - 1328 (2007/10/02)
Both arylacetonitriles and methyl arylacetates react with dimethyl carbonate (DMC) (20 molar excess) at 180 - 200 deg C in the presence of K2CO3 to produce monomethylated 2-arylpropionitriles and methyl 2-arylpropionates, respectively, with a selectivity >99.5percent.The reaction, with wide application, proceeds by DMC acting as a methoxycarbonylating agent towards the ArCH-X anion (X = CN, CO2Me) and as a methylating agent to ArC-(CO2Me)X.DMC also proved to be the best solvent for such reactions.
Photochemical Rearrangement of α-Chloro-Propiophenones to α-Arylpropanoic Acids: Studies on Chirality Transfer and Synthesis of (S)-(+)-Ibuprofen and (S)-(+)-Ketoprofen
Sonawane, Harikisan,Bellur, Nanjundiah S.,Kulkarni, Dilip G.,Ayyangar, Nagaraj R.
, p. 1243 - 1260 (2007/10/02)
A new single-step efficient photochemical approach for α-arylpropanoic acids (4) from α-chloro-propiophenones (5) is described.It involves carbonyl triplet excited state directed 1,2-aryl migration of the aryl group which has been found to be highly dependent upon the nature of the aryl substituent.The mode of the rearrangement is probed by the study of the photobehaviour of a set of optically active α-chloro-propiophenones.The results suggest that the nature of the carbonyl triplets (n, ?*/ ?, ?*) plays an important role in the chirality transfer.This method finds application in the synthesis of optically active ibuprofen (4e) and ketoprofen (26), though in moderate optical yields.
Oxidative decarboxylation of naproxen
Bosca,Martinez-Manez,Miranda,Primo,Soto,Vano
, p. 479 - 482 (2007/10/02)
The decarboxylation of naproxen (1H) and its salt (1-) was achieved by means of chemical [Ce(IV) or S2O8/2-] and electrochemical oxidation. The product patterns were compatible with mechanisms involving single-electron transfer from the pl-system or the carboxylate moiety. The results are discussed in connection with the involvement of electron-transfer processes in the reported phototoxicity of naproxen.
Manufacture of alpha-arylalkanoic acids and precursors
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, (2008/06/13)
α-Arylalkanoic acids or esters, orthoesters or amides thereof are prepared by forming an α-hydroxy ketal or thioketal of an aryl alkyl ketone, activating the α-hydroxy substituent with an esterifying agent to form the corresponding ketal or thioketal ester substrate, wherein the ester group is sufficiently labile to non-catalytically disassociate from the substrate in a protic or dipolar, aprotic solvent, maintaining the ester substrate in contact with the protic or dipolar, aprotic solvent or mixtures thereof for a time sufficient to form the corresponding α-arylakanoic acid or ester, orthoester or amide thereof, and optionally concomitantly or sequentially hydrolyzing any ester, orthoester or amide formed to the corresponding α-arylalkanoic acid.
