2- ethyl acetate, coupling

Hardcastle JL, Compton RG (2001) The electroanalytical detection and determination of copper in heavily passivating media ultrasonically enhanced solvent extraction by N-benzoyl-N-phenyl-hydroxylamine in ethyl acetate coupled with electrochemical detection by sono-square wave stripping voltammetry analysis. Analyst 126 2025-2031... 

Enantiomerically pure dipeptide is obtained when the /7-nitrophenyl ester of N-henzoyl-L-leueine is coupled with glycine ethyl ester in ethyl acetate ... 

Ethyl acetate is an oxygenated solvent widely used in the inks, pharmaceuticals and fragrance sectors. The current global capacity for ethyl acetate is 1.2 million tonnes per annum. BP Chemicals is the world s largest producer of ethyl acetate. Conventional methods for the production of ethyl acetate are either via the liquid phase esterification of acetic acid and ethanol or by the coupling of acetaldehyde also known as the Tischenko reaction. Both of these processes require environmentally unfriendly catalysts (e.g. p-toluenesulphonic acid for the esterification and metal chlorides and strong bases for the Tischenko route). In 1997 BP Chemicals disclosed a new route to produce ethyl acetate directly from the reaction of ethylene with acetic acid using supported heteropoly acids... 

The chemiluminescence reaction of esters of oxalic acid can proceed within a wider pH range than for luminol. However, the most efficient oxalate derivatives are only soluble in organic solvents such as ethyl acetate, acetonitrile, dioxane or dimethoxyethane and dissolution problems of these solvents in aqueous media are encountered. This can limit the use of this chemiluminescence reaction for a direct coupling to an H202-generating enzymatic reaction. 

Coupling 2-(acetoxymethoxy)ethyl acetate 791 with 801 gave 802, whose deacetylation gave 803 that on reaction with bromoacetone gave 804. Ace-... 

Conversion data listed in Table 2 indicate that in the hydrogenation of 4-amino-ethyl benzoate using cyclohexane as a solvent the AI2O3 supported Ru and Rh catalysts are more active than the carbon supported ones. In addition, the conversion of aromatic ester is smaller on Pd/C catalyst than on the carbon supported Ru and Rh. In ethyl acetate the hydrogenation proceeded slower than in cyclohexane, and Rh being more active than Ru. The trans/cis isomer ratio estimated from TLC results varied between 1/3 and 1/1. The UV active by-products were formed in coupling reactions. 

The residue was purified by silica gel chromatography (hexane-ethyl acetate, 30 1) to give the corresponding triflate (310.0 mg, 72%) as an oil, which was immediately used for the next cross-coupling reaction. 

The cross-coupling compound was isolated from the crude product by silica gel column chromatography (hexane/ethyl acetate 94/6-88/12). (0.104g, 87% yield). 

An indirect enzyme immunoassay suitable for the determination of chloramphenicol and its glucuronide was developed for the analysis of urine, milk, tissue, and eggs as well (48). In this assay, chloramphenicol succinate was coupled to both bovine serum albumin and horseradish peroxidase by a mixed anhydride procedure. Unlike tissue and egg samples, urine and defatted milk could be directly analyzed, but when an ethyl acetate extraction was employed in milk analysis, the limit of detection was lowered at least 10 times. 

The protonation behaviour of esters is closely similar to that of the parent acids. Birchall and Gillespie9 reported the observation of protonated ethyl acetate in HSO.,F-SbF5 solution at — 75°C, and concluded that protonation occurs on the carbonyl oxygen atom as in (4b), since they did not observe the spin-spin coupling between the added proton and the methylene group of the ether oxygen which would be expected if both were attached to the same atom, as in (4a). 

This protocol focuses on the analysis of chlorophyll a and b, and the more nonpolar derivatives, including pheophytins and pyropheophytins. An octadecyl-bonded, reversed-phase stationary phase is used with a methanol/water mixture and ethyl acetate mobile phases in a gradient elution to provide rapid and complete separation of the major chlorophyll derivatives in 25 to 30 min. This is coupled with traditional UV/visible spectrophotometric detection at 654 nm to selectively screen these photosynthetic pigments in food and plant tissues. 

Synthesis of the benzopyran ring has also been performed by microwave-assisted copper-catalysed cross coupling of an aryl iodide with terminal alkynes, in the presence of copper(I) iodide/triphenylphosphine (Scheme 3.35)56. An alternative approach involving microwave heating of mixtures of salicylaldehyde and various derivatives of ethyl acetate in the presence of piperidine has enabled rapid Knoevenagel synthesis of coumarin derivatives (Scheme 3.35)57. 

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