Ibuprofen, generation

Ester alcoholysis (transesterification) in organic media is an equilibrium reaction and must be shifted in the desired direction. For example, Bornscheuer and coworkers [61] reported the resolution of ibuprofen vinyl ester by transesterification tvith n-hexanol in the presence of CAL-B. The vinyl alcohol generated during the reaction tautomerizes to acetaldehyde, thus making the reaction irreversible, as illustrated in Figure 6.14. 

An example of monotropic behavior consists of the system formed by anhydrous ibuprofen lysinate [41,42], Figure 4.12 shows the DSC thermogram of this compound over the temperature range of 20-200°C, where two different endothermic transitions were noted for the substance (one at 63.7°C and the other at 180.1°C). A second cyclical DSC scan from 25 to 75°C demonstrated that the 64°C endotherm, generated on heating, had a complementary 62°C exotherm, formed on cooling (see Fig. 4.13). The superimposable character of the traces in the thermograms demonstrates that both these processes were reversible, and indicates that the observed transition is associated with an enantiotropic phase interconversion [41]. X-ray powder (XRPD) diffraction patterns acquired at room temperature, 70°C, and... 

Replacement of tppts by a ligand containing less -S03Na groups such as tppms gave rise to a dramatic drop in the catalytic activity and selectivity to ibuprofen. A palladium catalyst generated from the sulfonated diphosphine 29 (Table 2 x=3 m=n=0 86% and m=0,n=l 14%) exhibited low catalytic activity and the major product was 3-IPPA (78%).451... 

Celanese process for the manufacture of ibuprofen on a 3500-ton scale has been operating since 1992. In this process isobutyl benzene is acylated and then hydrogenated over a heterogeneous catalyst to give the appropriate precursor alcohol. This alcohol is then carbonylated. The overall synthetic scheme is shown by reaction 4.14. The conventional process for ibuprofen manufacture was based on six synthetic steps and generated a large amount of salt as a solid waste. 

With the present design, a data base of fifty selected starting materials, and two hundred selected reaction rules SYNLMA is currently able to generate synthetic trees, often in a very naive or inefficient manner, for molecules of the size and complexity of Darvon, Ibuprofen,... 

Data generated following i.v. doses of R-ibuprofen to humans provides strong evidence suggesting systemic inversion of ibuprofen from R to S, as no significant differences were noticed between oral and intravenous routes of administration in healthy subjects [104]. However, solutions of R-ibuprofen were administered in this study, whieh may be absorbed so rapidly that a negligible amount of the dose may eontact the... 

The formation of C-C bonds is of key importance in organic synthesis. An important catalytic process for generating C-C bonds is provided by carbonylation. Most carbonylation reactions have a good atom economy, because most reagent atoms are transferred to the product. Therefore, there are some applications of carbonylation processes in fine chemistry, too. For example, the analgesic ibuprofen is produced by Hoechst-Celanese by carbonylation of a substituted alcohol with 100% atom efficiency according to Eq. (8-20) [7] ... 

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