Ibuprofen side-chain oxidation

The main metabolites of ibuprofen, the glucuronides of ibuprofen and of the side-chain hydroxylated derivative 2-[4-(2-hydroxy-2-methylpropyl)phenyl]propionic acid) and a side-chain oxidized compound 2-[4-(2-carboxy-2-methylpropyl)phenyl]-propionic acid) could be detected after SPE using a 250-MHz instrument (Figure 8-2) [10]. 

A number of papers have appeared on the use of layered double hydroxides (e.g. Mg and Al containing oxides). A meixnerite-like catalyst has been reported to give 100% selectivity for diacetone alcohol from acetone at 0 C at close to thermodynamic equilibrium conversion of 23% (Tichit and Fajula, 1999). The side-chain alkylation of toluene with propylene to give isobutyl benzene (for ibuprofen) is a well-known example where Na/K alloy on Na2C03/K2C03 is used as the catalyst. 

Some biotransformations introduce an asymmetric center into a drug and these often proceed stereospeci-fically. The most common examples are hydroxylation of a secondary carbon and the reduction of ketones to secondary alcohols. Ibuprofen undergoes both co and co-l oxidation of the isobutyl side chain, and formation of the resulting carboxylic acid metabolite introduces a second asymmetric center into the molecule. Both ibuprofen enantiomers have been shown to undergo stereospecific oxidation to give a metabolite with the same configuration at the new asymmetric center. 

Aryl Acetic Acids - The a-methyl homolog of ibufenac (Dytransin), ibuprofen (VI), is 4 to 8 times more active ib anti-inflammatory, analgesic and antipyretic assays, but the increased potency was not confirmed in a brief clinical study. Unlike other aryl acetic acids,both d and 1 enantiomorphs are active in animals, although only dextro-rotatory metabolites with oxidized isobutyl side-chains were isolated as principle urinary metabolites. ... 

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