As mentioned in number 13, the data for the melting point makes sense because my pure product and given compound almost perfectly matched. 17. Again as explained in number 14, the TLC data made sense because my pure compound and 4-tert-butylbenzyl phenol had similar distances from the solvent origin of the plate. The presence of benzyl bromide and benzyl alcohol also explains how not all the product dissolved in the filtrate.
The selectivity to methanol was found to be larger than 95%, with the low conversion condition and CO2 as the only by-product. The skeletal copper catalyst deactivated fast, this was found to be from fouling caused by polymeric material building up. Copper chromite catalyst did not experience deactivation. Monti et al. investigated gas-phase hydrogenolysis of methyl formate over silica supported copper catalyst.
In this experiment, extraction was used as a separation technique to separate the acid, base, and neutral compounds. In extraction, two immiscible solvents with opposite polarities are used to dissolve different parts of the solute with different polarities, so they form two distinct liquid layers. In this experiment, methanol, an organic solvent, and an aqueous solution were used as the two immiscible solvents. The extraction solvent must also be capable of dissolving one of the mixture components. While initially it seems as though methanol, an organic solvent would be incapable of dissolving a polar acid or base, the conjugate of the acidic and basic compound will dissolve in methanol.
Rf is equal to the distance traveled by the substance divided by the distance traveled by the solvent. Since the solvent used in the developing chamber was hexanes—a non-polar molecule— the more nonpolar the substance was, the stronger it would stick to the plate. This means that the more polar a pigment was, the higher it climbed on the TLC plate and would therefore have a larger Rf. There are 3 major classes of pigments present in spinach: carotenes, xanthophylls, and chlorophylls. Since the solvent is nonpolar, we would expect carotene to have the lowest Rf, then xanthophylls, and chlorophylls would have the highest.
One noticeable exception is the so-called “Atwal modification” of the Biginelli reaction. In this scheme, an enone(a) is first condensed with a suitable protected urea or thiourea derivative(b) under almost neutral conditions. Deprotection of the resulting 1,4-dihydropyrimidine(c) with HCl or TFA leads to the desired DHPMs.20 Scheme-3: Shutalev et al described another approach to DHPMs synthesis. This synthesis is based on the condensation of readily available R-tosylated (thio)ureas(a) with the enolates of acetoacetates or 1,3-dicarbonyl compounds. The resulting hexahydropyrimidines(b) need not to be isolated and can be converted directly into DHPMs.
In addition, methyl ether (**) can be generated as cis- and trans- isomers, but was isolated as a single isomer. This compound was stable against heat at 60 degrees and was not transformed into 5-trifluoromethyl oxazole (**), whereas compound (*) was unstable, turned into easily rearrangement oxazole (**) in the middle of isolation. To confirm this rearrangement of compound (*), when we heated at 60 degrees for 30min, the compound (*) was observed to convert into oxazole (**)
Conversely, cationic surfactants such as cetyltrimethyl ammonium bromide (CTAB) release a positive charge in an aqueous solution. On the other hand, in alkali pH, amphoteric surfactants act as anionic while in acid pH, it act as cationic. Non-ionic surfactants such as partially hydrolyzed PVA (polyvinyl alcohol) have no charge (Li et al, 2008). Among four types of surfactants, partially hydrolyzed PVA is most frequent used because it gives the smallest microsheres (Jeffrey et al, 1991). The amount of PVA used may affect microparticles properties.
The melting point of the experimentally synthesized Aspirin product was found to be between 126-129 ˚C. This temperature range of initial to final melting point has a small and sharp temperature range of only 3˚C, which is within the acceptable limits of the 128-137˚C1 literature value for Aspirin (Acetylsalicylic Acid/2-acetoxybenzoic acid), if located slightly toward the beginning of the literature melting temperature range. Therefore, the narrow melting point range, which falls within the standard literature value range results, indicate the reliability purity of the sample. Had the melting point been higher than the literature value, but maintained a sharp melting point range, the compound could have still indicated a pure sample. A lower
Con Decon Process : It is a dilute chemical decontamination process that avoids the draining or flushing of the system to be decontaminated. It is also not necessary to defuel the reactor due to decontamination process. This is thus a simplified process which results in cleaning of the fuel at the same time, adding a huge advantage of removing a significant amount of activated corrosion product which if allowed to remain would eventually dissolve and redeposit out-core, thus partially negating the effects of the decontamination.
Even if the dehydration is not spontaneous, it can usually be done easily, since the new double bond will be in conjugation with the C =O bond. Ritter Reaction Alcohols is converted by a strong acid to a carbocation, which adds to the negative nitrogen. The immediate product tautomerizes to the N-alkyl amide. Only alcohols that give rise to fairly stable carbocation react; primary alcohols do not give the reaction.
Butyl ethanoate has a fruity smell and can be described as a pear smell. Its molecular formula is CH3COOCH2CH2CH2CH3 and, like in this experiment can be produced from butanol and acetic acid. Butyl ethanoate is a colourless, flammable liquid which often is used in organic chemistry as a solvent. In industry, butyl ethanoate is used to manufacture lacquers, artificial leather, photographic films, plastics and safety glasses. Due it it’s fruity, pear odour it is used in flavouring and fragrance, however at extremely high concentrations butyl ethanoate is toxic
In order for a substance to be pure, its melting point, from start to finish, must stay within 3 oC or 4 oC because more pure organic substances melt within the range of 1 oC – 2 oC. (Craine et al., 2012) The range of the crude was 5.3 oC, a clear indication of impurity. In addition, it was well below the literature melting point of 9,10-dihydroanthracene-9,10-α,β-succinic anhydride at 262 oC – 264 oC, which was another indication of impurity. However, the pure product had a melting point of 260.3 oC – 263.9 oC, which was much closer to the melting point of the pure product and stays within the range of 3 oC – 4 oC, which could indicate that there was still a small amount of impurity, but the product attained was close to a pure
Observations The purpose of this experiment was to be able to synthesize triphenylmethyl bromide from triphenylmethanol by a trityl carbocation intermediate. During the experiment, 0.100 g of triphenylmethanol was placed into a small test tube. The triphenylmethanol looked like a white powder. Next 2 mL of acetic acid was added to the test tube and the solution turned a cloudy white color.
Introduction The purpose of this week’s lab was to enhance our understanding of the Grignard reagents that were examined in lecture. In this lab, a Grignard reagent will be prepared through the reaction of magnesium turnings and bromobenzene. Instead of isolating the product it will then be combined with benzophenone, which will give the final product of triphenylmethanol. Procedure
Purpose In this experiment, the limiting reactant of a chemical reaction and the percent by mass composition of a mixture were determined. An unknown salt mixture containing sodium phosphate and barium chloride dihydrate was added to water producing a mixture containing a solid precipitate of barium phosphate. Through the use of filtration, the precipitate was removed from the mixture completely. The filtered liquid was transferred into multiple test tubes, each test tube had either barium chloride or sodium phosphate added into the liquid.