JanuPatelExp015


 * Why is ether used as the primary extraction solvent in Experiment015 ?**

From the log of [|Exp015:] 19:13] Poured solution without excess NaCl into a separatory funnel. Extracted with 17mL anhydrous ether 19:20] Extracted with 10mL anhydrous ether 19:24] Extracted with 10mL ether

(The follow information is collected from this [|site] and this [|site] ) The most common way to extract dissolved substances from aqueous solutions is by the almost water-insoluble solvents - An important intermediate product in the Ugi synthesis of diketopiparzine antimalarial targets is DOPAL. - Despite reasoning to believe that [|DOPAL] was soluble in methylene chloride (from reported purification of DOPAL using cholorform in hexanes), it was seen that adrenaline bases were not that soluble in chlorinated solvents. - Ether, however, was an optimal solvent for DOPAL was extracted in it. - Illustrating ether’s properties as being an excellent extraction solvent, it was used greatly in this experiment - Readily removed by evaporation, it is best to use in a product which has a relatively low boiling point. - Ether molecules, weakly basic compounds, are used over dichloromethane due to varying physical properties of each compound - Being an immiscible solvent, it easily forms two layers in the separatory funnel so as to make the extraction much easier. - Since their carbon-oxygen bonds are not readily detached, ethers are fairly unreactive compounds - Thus, they are frequently used over dichloromethane due to the fact that so many neutral organic compounds are soluble in it - In addition, dichloromethane is not highly soluble in water, which would not make for an optimal extraction solvent //**the opposite is true - that makes dichloromethane a good extraction solvent as well**// - For example, at 20 degrees, [|diethyl ether] is soluble to extent of 6.9g in 100ml of water - [|Dicholormethane], on the other hand, is less soluble and is only soluble 1.3 g in 100mL at 20 degrees - Another disadvantage is that after a long period of time the vapors of the dicholormethan become dangerous - The solution of glycerol, phosphoric acid, and NACL, which is being extracted best responds to the properties of ether and thus result in a better separation scheme than dichloromethane - The slightly polar C-O-C bond in the functional group of the ether causes for a better solvent as compared to the nonpolar dichloromethane - Dicholormethan is nonpolar due to the fact that carbon shares the hydrogen molecules uniformly. //**wrong dichloromethane is polar - see p. 12 of the pdf from**// [|this lecture] - Also the two chlorine molecules cancel out each other's polarity and leaves the molecule in a symmetrical fashion. ( with no associated polarity) - The presence of two lone pairs of electrons on the oxygen atoms makes hydrogen bonding with water molecules possible, which is not possible in dichloromethane

==( The solubility properties of polar and nonpolar substances along with their bonding patterns playing roles in solubility have been seein in [|Lecture 07.)]==

[|Diagram of Ether Molecule:] [[image:800px-Diethyl-ether-3D-vdW.png width="334" height="207"]].
=Grade: 7/10=