Ethyl lactate-water system

Reaction conditions Ethyl lactate-water system (as a bio-based green solvent), room temperature... 

Keywords Isatins, naphthaquinone, proline, ethyl lactate-water system, bio-based green solvent, room temperature, 1,3-dipolar cycloaddition, one-pot three-component reaction, spiro-oxindoles, spiro[benzo[/]pyrrolo[2,l-fl]isomdole-5,3 -indoline]-2, 6,ll-triones... 

A mixture of isatin (1 1 mmol), proline (2 1 mmol) and 1,4-naphthoquinone (3 1 mmol) in ethyl lactate-water system (5 mL 80% ethyl lactate in water v/v) was stirred magnetically at room temperature for stipulated time (20-55 min). On completion of the reaction (as indicated by TLC), the reaction mixture was left overnight. The precipitate was isolated by filtration and washed with water to furnish pure spiro[benzo[f]pyrrolo[2,l-a]isoindole-5,3 -indoline]-2, 6,ll-trione 4. Each of the products was characterized by analytical and spectral studies. 

Solubility in the solvent selected for application Currently the organic solvent are replaced with water as a suspension system, although certain types of film coatings may require organic solvents to be used. Commonly used solvents include alcohols (methanol, ethanol, and isopropanol), esters (ethyl acetate and ethyl lactate), ketones (acetone), and chlorinated hydrocarbons (dichlo-romethane and trichloroethane). 

To evaluate new filter and/or purifier technology placed in distribution or recirculation lines, ICP-MS has been applied to analyze impurities in ethyl lactate, ethyl 3-ethoxy propionate, propylene glycol monomethyl ether acetate and 2-heptanone, water and IPA, or diluted HF. ICP-MS is also the recommended technique to evaluate the purity of polymer eomponents used in UPW and liquid chemical distrihution systems. It has also heen applied to evaluate the relative effectiveness of various acids for extracting impurities from components made of different types of fluorinated polymers. ... 

Figure 20.4.9. Vapor-liquid equilibria of the (water -I- ethyl lactate) system at 333K. [Data from D.T. Vu, C.T. Lira, N.S. Asthana, A.K. Kolah, and D.J. Miller, J. Chem. Eng., 51, 1220 (2006).]...

In Sections 20.4.2.1 and 20.4.2.2, the liquid-liquid phase boundary at ambient pressure of binary and ternary systems comprising ethyl lactate and lipid-type substances is reviewed, and potential industrial applications based in the LLE observed are introduced. Further, in Section 20.4.2.3, the solubility of several high-value food compounds in ethyl lactate is presented and compared with the solubility in water. Finally, high pres-... 

Transition temperatures define the liquid-liquid region of a system and are usually determined by the cloud-point mefliod, i.e. observing visually the onset of the phase transition. In general, mixtures of ethyl lactate wifli lipid-type substances exhibit partial liquid-liquid miscibility below certain temperature (die upper critical solution temperature, UCST) as is depicted in Figure 20.4.10 for the (squalene + ethyl lactate) and (olive oil + ethyl lactate). In these cases, the cloud-point was experimentally measured as follows a vial containing the sample was introduced in a water bath and was heated to up to temperature at which the system attains homogenous liquid phase then, heating is... 

Tables 20.4.8 to 20.4.10 and Figure 20.4.11 present the liquid-liquid transition temperatures at ambient pressure of the binary (ethyl laetate + olive oil) system, the pseudo-binary (ethyl lactate + olive oil containing 11.60 wt% of oleic acid) and (ethyl lactate containing 2.80 wt% of water + olive oil). Cloud points at atmospheric pressure were visually detected based on solution turbidity in equilibrium glass cell placed in temperature controlled bath.

On the oflier hand, water has a strong anti-solvent effect in this type of mixture. For example, the presence of 2.80 wt% of water in ethyl lactate increased the UCST for approximately 39K, producing higher immiscibility of the system. Figure 20.4.13 presents the UCST of the (olive oil + ethyl lactate) mixture as a function of the water content in ethyl lactate The linear regression of data presented in Figure 20.4.13 reveal that the presence of 0.1 wt% water in ethyl lactate solvent leads to 1.4K increase of UCST. 

However, morpholine-4-carboxylic acid 2-hydroxy-1-methyl-ethyl ester is formed by the reaction of PC and the substrate morpholine in an undesired side reaction. By use of 1.4-dioxane or the pyrrolidones as mediator s3 about 30 to 45% of the morphoUne is consumed by this side reaction. The by-product is contained in the PC phase and can not be extracted to the non-polar product phase. The selectivity to the desired amines is lowered, because of the consiunption of the morphoUne. Thus, PC has to be substituted by another polar solvent (e.g. water, methanol or ethylene glycol) in future experiments. The lactates react with the morphoUne, too resulting in the corresponding amide. Overall, the hydroaminomethylation in the TMS systems PC/dodecane/lactate results in a conversion of 1-octene of about 80%, but in selectivities to the amines of only 50 to 60%. 

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