MAP esters

MAP ester compositions have received significant attention because of their combination of excellent detergency and abundant, lubricious foam production with low irritation. These properties are particularly desirable in cosmetic and personal care applications. The dialkyl ester contributes to a reduction in water solubility, foam generation, and detergency properties. Hence, considerable effort has been devoted to the development of economical and simpler methods to produce high monoalkyl ester compositions. 

Kao [48] has reported an elaborate, extractive process to produce 96 wt% MAP containing only 2.3% phosphoric acid and <1% each of DAP and unreacted alcohol. The process uses a fivefold molar excess of polyphosphoric acid (105%) to alcohol, thereby minimizing unreacted alcohol in the product. Because of the high viscosity of the intermediate product, the reaction is carried out in hydrocarbon (hexane) solvent. On completion of the reaction, additional hexane is added and the mixtnre is extracted with isopropanol. The hexane and aqueous layers are then separated. The hexane layer containing the MAP ester is extracted for the second time with aqueous isopropanol, then any residual water and isopropanol are removed by azeotropic distillation with continuous hexane addition. The hexane fraction is cooled, allowing the monoalkyl ester to crystallize. It is filtered and the residual hexane is distilled for recycle. The water-isopropanol extracts containing phosphoric acid are then stripped to recover the phosphoric acid for recycle. This batch process can be adapted to a continuous operation. Several refinements of this process have been published [49-51]. 

Initially, multiple-step processes evolved, which could be conducted sequentially in a single reactor. These processes alternate the addition of phosphoric anhydride, water, alcohol, and hydrogen peroxide in a complex sequence to produce high MAP esters. To fill the need for a solvent to maintain reasonable viscosity throughout the process but avoid the necessity of its removal, the phosphate ester mixture itself could be used as a solvent [32,33]. 

Acid anhydride, amides from, 807 eleclrostatic potential map of, 791 esters from, 807 from acid chlorides, 806 from carboxylic acids, 795 1R spectroscopy of, 822-823 naming, 786... 

Backbone (protein), 1028 Backside displacement. reaction and.363-364 von Baeyer, Adolf, 113 Baeyer strain theory, 113-114 Bakelile, structure of, 1218 Banana, esters in, 808 Barton, Derek, H. R., 389 Basal metabolic rate, 1169 Basal metabolism. 1169-1170 Base, Bronsted-Lowry, 49 Lewis, 57, 59-60 organic, 56-57 strengths of, 50-52 Base pair (DNA), 1103-1105 electrostatic potential maps of. 

Thomas, S. M., DeMarco, M., D Arcangelo, G., Halegoua, S., and Brugge, J. S. (1992). Ras is essential for nerve growth factor- and phorbol ester-induced tyrosine phosphorylation of MAP kinases. Cell 68 1031-1040. 

Wang, X., Flynn, A., Waskiewicz, A. J., Webb, B. L. J., Vries, R. G., Baines, I. A., Cooper, J., and Proud, C. G. (1998). The phosphorylation of eukaryotic initiation factor eIF4E in response to phorbol esters, cell stresses, and cytokines is mediated by distinct MAP kinase pathways. J. Biol. Chem. 273, 9373-9377. 

A process research investigation on p38 MAP kinase inhibitors examined the synthesis (on 7 mol scale) of a group of closely related pyrimidinones such as 37, by condensation of a number of arylacetic esters with 4-cyanopyridine and methyl isothiocyanate. Other nitriles were also examined but were much less successful than 4-cyanopyridine 3-cyanopyridine gave a much lower yield and both benzonitrile and 2-cyanopyridine failed completely <06T11714>. 

An overall picture of similarity between [C4CiIm][PFg] and conventional solvents is given by the so-called nonlinear map, or Sammon map [20] in Figure 9.5. The closer the points representing solvents on the map, the more similar the solvents are. As is seen, the position of the IL on the map is between esters and aromatic hydrocarbons. 

Solvation effects on the conformation of esters of three /i-snbstituted 1-phenyletha-nols with 2-flnoro-2-phenyl acetic acid (FCDA) were studied both experimentally (in five solvents ranging from CDCb to DMSO) and quantum mechanically. Semi-empiri-cal (AMI of MJS Dewar and PM3 of JJP Stewart) and ab initio (RHF/3-21 G) calculations were undertaken. Energy maps for the conformers of the esters as a function of the dihedral angles alpha (F-C-alpha acid-C=0) and beta (CO-O-C-alcohol-H) were obtained. Solvent effect calculations, through the self-consistent reaction field on the most stable conformers, were also carried out (Hamman et al., 1996). 

Restriction endonucleases catalyze the hydrolysis of specific phosphodi-ester bonds in double-stranded DNA. These enzymes are often used to linearize a circular plasmid for hybrid DNA construction. They have also found use in the analysis of DNA and the construction of restriction maps. In this experiment, students will incubate various restriction enzymes with plasmid or viral DNA and analyze the product DNA fragments by agarose gel electrophoresis. 

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