2292-53-7Relevant articles and documents
Preparation of hydroxamic acids from esters in solution and on the solid phase
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Page/Page column 3, (2010/02/15)
The present invention provides a novel method for the formation of hydroxamic acids comprising reacting under suitable conditions an ester with hydroxylamine in the presence of cyanide anion.
Controlled racemization and asymmetric transformation of α-substituted carboxylic acids in the melt
Ebbers, Eelco J.,Ariaans, Gerry J. A.,Bruggink, Alle,Zwanenburg, Binne
, p. 3701 - 3718 (2007/10/03)
The racemization and asymmetric transformation of a series of α- substituted carboxylic acids, viz. mandelic acid, hydratropic acid, ibuprofen and naproxen, were studied. Several racemization methods for mandelic acid were studied and it was found that base-catalyzed racemization in aprotic polar solvents was the most efficient method. Moreover, a fast and mild base- catalyzed racemization reaction in the melt was developed. DBN turned out to be a very efficient racemizing base for the substrates studied. Combination of the base-catalyzed racemization in the melt with known resolution processes resulted in crystallization-induced asymmetric transformations. Treating racemic ibuprofen or hydratropic acid with 1.5-2.5 equivalents of enantiopure α-methylbenzylamine and a catalytic amount of DBN resulted in the isolation of enantiomerically enriched ibuprofen or hydratropic acid with ees of up to 75% and almost quantitative yields.