Abstract – Methyl trans-cinnamate is an ester that contributes to the aroma of strawberry. It can be synthesized by an acid-catalyzed Fischer esterification of a methanol and trans-cinnamic acid under reflux. The solution was extracted to obtain the organic product, and evaporated residual solvent The yield was 68%, but there is some conflicting data regarding the purity. The melting point, IR, GC-MS indicate a highly pure desired product whereas 1H NMR shows there are unreacted reagents still present. Introduction: The purpose of this experiment is to synthesize the component of strawberry fragrance – methyl trans-cinnamate. This reaction is accomplished by a Fischer esterification of methanol and trans-cinnamic acid refluxed for 1 hour …show more content…
The literature melting point range of methyl trans-cinnamate is ~34-38oC (Aldrich).4 The obtained melting point of the crude was 34.5-35.5oC, which is a highly narrow range of less than 1oC difference and it also falls within the expected melting point range. Hence, the crystal lattice structure of the product is largely intact, requiring an even amount of thermal energy to melt the sample. The experimental melting point range indicates the crude product is relatively pure with minimal impurities. The percent yield was satisfactory, having a 68% yield. To optimize this yield, consider the steps in how the reagents are introduced to the reaction mixture in terms. It is understood the mechanism is acid-catalyzed where protons coordinate with the carbonyl oxygen to make the carbonyl carbon more electropositive for nucleophilic attack (Scheme 1). In the experimental procedure all reactants were added together, this is inefficient as the protons can coordinate with either trans-cinnamic acid or methanol. Coordination with methanol is unnecessary as it reduces its nucleophilicity and makes less protons available to coordinate with the carboxylic acid. To improve …show more content…
This supports the isolated product is majority made of the desired product and is largely pure. Mass spectrometry of the crude product shows the molecular ion peak is 162.1, which is the largest fragment in the mass spectrum (Figure 4) and corresponds to the molecular weight of methyl trans-cinnamate (Table 1). The base peak is 131, inferring the fragment lost is 31 m/z in size. This 31 m/z matches the OCH3 fragment of the ester, and would not result from a trans-cinnamic acid. This is evidence the product was successfully
C4564 Description: IC50: 3-AP is a ribonucleotide reductase inhibitor and iron chelator with antitumor activity. Ribonucleotide reductase, the rate-limiting enzyme for de novo DNA synthesis, is an excellent target for chemotherapy. Its increased activity in cancer cells is associated with malignant transformation and proliferation.
At this point I found that if the hot plate was at 147˚C the solution boiled more vigorously, meaning that my ketone hade a boiling point of 147˚C, which was close to the known boiling point value for 3-heptanone , 146˚C. The hot plate was turned down after this was noticed. After the solution was heat, approximately for five minutes, the mass was found for the bottom layer, which was 2.27g, and the percent yield was calculated. The percent yield was determined by taking the mass of the final ketone and dividing it by the original mass of the alcohol.
The melting point of the product was observed to be 139.5 °C. The theoretical yield of the product is 152 °C (University of South Carolina Department of Chemistry and Biochemistry). The melting point percent difference was calculated by subtracting the theoretical melting point from the actual melting point, dividing the result by the theoretical melting point, and multiplying the result by 100%. The melting point difference was 8.22%. Example calculations are shown
K.D.A. Saboia et al. , (2007) have been prepared the Bi4Ti3O12–CaCu3Ti4O12 {[BIT(X)–CCTO(100-X)]} composite powders through solid state reaction method and calcined in the range of 900 to 1020 ºC for 12 h. The as-prepared powders have modified in the form of thick film onto alumina ceramic substrate by utilizing screen printing. At 100 Hz, the value of dielectric constant (κ) of CCTO100 and BIT100 is 316.61 and 53.64 respectively. Conversely, the composite with X=20 % shows an unexpected dielectric constant of 409.71, which is around 20% higher in comparison with the CCTO.
1. Identify the range of senses involved in communication • Sight (visual communication), Touch (tactile communication), Taste, Hearing (auditory communication), Smell (olfactory communication) 2. Identify the limited range of wavelengths and named parts of the electromagnetic spectrum detected by humans and compare this range with those of THREE other named vertebrates and TWO named invertebrates. Figure 1: the electromagnetic spectrum source: www.ces.fau.edu Vertebrates Human Japanese Dace Fish Rattlesnake Zebra Finch Part of electromagnetic spectrum detected ROYGBV (visible light) detected by light sensitive cells in the eye called rods and cones.
The reaction to synthesize benzocaine was known as a Fisher esterification reaction. The Fisher esterification was reaction between alcohol and carboxylic acid in the presence of acid. The reaction was used to form an ester. In the experiment, sulfuric acid acted as a catalyst and necessary for this reaction to occur. There was a change between the –OH group of carboxylic acid to an –OCH2CH3 group in the reaction.
9. The melting point range was lower than the given range of the anti-addition product by 2 degrees Celsius. This could have been due to impurities in the product. A likely cause could have been water that still remained in the product after recrystallization (the product shifted upward during melting point analysis due to evaporation). Since water has a low melting point, it could have lowered the melting point range of the product.
As seen in table 1, the theoretical yield was .712 g of C_17 H_19 NO_3. The % yield of this experiment was 7.51 % of C_17 H_19 NO_3. . This low yield can be explained from a poor recrystallization technique combined with potential contamination. Throughout the experiment, the mixture changed color from green, orange, to yellowish lime, and eventually clear.
"Two Enzyme Catalysis." Article. n.d.: 19-21. Reece, Jane B., Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, and Robert B. Jackson. "
The purpose of this experiment was to identify the two components of an unknown mixture through diverse experimental techniques such as recrystallization, extraction, melting point, and acid-base reactions. From this, the group to which these two compounds belong to had to be determined. These groups are: Carboxylic Acids, phenols, and neutrals. By determining the melting points of the two unknown compounds, these values were compared to the values of melting points in the chart and the proper compound was selected. For the case of this experiment, the unknown mixture contained, 4-methylbenzoic acid.
Tn 4351 was originally isolated from bacteroides fragilis [30] . The transposon was successfully introduced into Cytophaga succinicans, Flavobacterium meningosepticum, Flexibacter canadiansis, Flexibacter strain SFI and Sporocytophaga myxococcoides by conjugation [25]. Tn 4351carries two antibiotic resistance gene. One of the codes for resistance to erythromycin and clindamycin which is expressed in bactroides but not in E.Coli. The other gene codes for resistance in tetracycline and is expressed in aerobically grpwn E. coli, but not in anaerobically grpwn E. coli or in bacteroides.
The purpose of this experiment was to learn about metal hydride reduction reactions. Therefore, the sodium borohydride reduction of the ketone, 9-fluorenone was performed to yield the secondary alcohol, 9-fluorenol. Reduction of an organic molecule usually corresponds to decreasing its oxygen content or increasing its hydrogen content. In order to achieve such a chemical change, sodium borohydride (NaBH4) is used as a reducing agent. There are other metal hydrides used in the reduction of carbonyl groups such as lithium aluminum hydride (LiAlH4).
Energy, from the most microscopic of organisms to the great whales of the sea all share one thing in common they need energy to live. In the mitochondria of all eukaryotic organisms the Citric Acid cycle or Krebs Cycle as it is also commonly known is an eight step intercut process embedded in the energy yielding cellular respiration sequence. Early on in the first research done on the Citric Acid Cycle biologists could not understand how the pyruvate that was made from glycolysis was eventually used by the Citric Acid Cycle. It wasn’t until Hans Krebs suggested in 1953 that the reactions were indeed more of a cyclical cycle and that the one reaction’s product was directly used as another’s reactant. For these finding Krebs won the Nobel Prize
Results 8. The obtained product was 4-tert-butylbenzyl phenol ether. This leads the unknown compound # 51 to be tert-butyl phenol. 9. Theoretical yield =
It has a boiling point of 102°C and a melting point of -95°C. Furthermore, Methyl butyrate is a colourless liquid and has a fruity odour resembling apples or pineapples. It can be produced by distillation of essential oil from vegetables. It is manufactured in small scale for use in perfumes and food flavouring. Moreover, it is less dense than water and is slightly soluble in water.