Esters partial

The difficulties attendant with the direct preparation from alcohol and phosphorus halide of partial ester/partial halide systems may be overcome through the use of a variety of alternative approaches. We will briefly consider a few of these here. 

This method permits the direct determination of TBARS in oils and fats without preliminary isolation of secondary oxidation products. This protocol is applicable to animal and vegetable fats and oils, fatty acids and their esters, partial glycol esters, and similar materials (AOCS, 1998). 

Fatty acid ethoxvlates Fatty acid esters Partial glycerides Triacetin... 

Unlike the situation with ampicillin, the introduetion of asymmetry at the a-ben/.yl carbon in carbenicillin imparts little or no stereoselectivity of antibacterial action the individual enantiomers are nearly equally active and readily epi-nierixcd to the racemate in aqueous solution. Because it is a derivative of phenylmalonic acid, carbcnicillin readily de-carboxylatcs to bcn/.ylpenicillin in the presence of acid therefore, it is not active (as carbcnicillin) orally and must be administered parenterally. Esterification of the compound from acid-cataly/ed destruction and provides an orally active derivative that is hydrolyzed to carbenicillin in the plasma. The plasma levels of free carbenicillin achieved with oral administration of such esters, however, may not suffice fur effective treatment of serious infections caused by some species of Gram-negative bacilli, such as P. aerttgi-no.sa. 

Feedstocks which can be completely vaporized, can be treated in gas phase processes. At the conditions prevailing in the reactor (250 0-300 bar), several hundreds mol of hydrogen must be fed per mol of ester and, sometimes, methanol is needed to dilute the gas stream and to decrease the ester partial pressure. The energy necessary to drive the recycle compressor is therefore very important. The liquid space velocity is c. 0.35 hr . The absence of liquid in the reactor enables to use an unsupported catalyst of high activity. This catalyst is a promoted copper oxide which is very resistant to poisoning. The consumption of catalyst is less than 0.3. This catalyst is very pyrophoric it must be reduced inside the reactor. As the amount of catalyst per unit volume of reactor is higher than in slurries, the selectivity is also higher it can reach 9 Plants of 12000 t/a capacity have been built. 

Potassium hydroxide Carboxylic acids from their esters Partial hydrolysis... 

In general the reduction of a pyridine side-chain acid or ester using platinum oxide, Raney Nickel, rhodium-on-carbon, rhodium-on-alumina, or ruthenium oxide as the catalyst gives the piperidine acid or ester. Partial reduction of the pyridine ring to a tetrahydropyridine usually occurred when palladium-on-carbon was employed as the catalyst, although two exceptions were reported. Either a mixture of the piperidine and the tetrahydropyridine ester or the tetrahydropyridine ester alone was formed when sodium borohydride was used at room temperature in the reduction of pyridine side-chain ester salts. When the free bases were employed, reduction of the ester group occurred instead of nuclear reduction. The use of lithium aluminum hydride gave the same results (see Table XI-18). Many acetamides... 

Synthesis and Characterisation of Sucrose Esters. Partial sucrose esters were used as starting materials having the general formula Sue (OR) (OH) where n =... 

Hydroxy-o-nitrocarboxylic acid esters from cyclic o-nitroacetals via 2-hydroxy-o-nitrosocarboxylic acid esters Partially protected carbohydrate derivs. 

Potassium permanganate Phosphoric from phosphorous acid esters Partial hydrolysis of phosphites s. 12, 161 Arsacridone oxides from 5,10-dihydroarsacridines s. U, 989... 

Chem. Descrip. Phosphoric acid ester partially neutralized with triethanolamine Chem. An ysis 3.94.5% N 6.3-71% P CAS 102-71-6 EINECSCLINCS 203-049-8... 

Chem. Descrip. Org. phosphate ester, partial sodium salt Ionic Nature Anionic... 

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