Abstract In this experiment methyl-3-phenyl-2-propenoate was prepared using a Wittig reaction. Benzaldehyde and methyl (triphenylphosphoranylidene) acetate were used to give a final product. 0.33g of methyl3-phenyl-2-propenoate was found at the end of the experiment therefore the percentage yield of methy-3-phenyl-2-propenoate is 62%. The Rf value of benzaldehyde was found to be 0.85. The Rf value for methyl-3-phenyl-2-propenoate was found to be 0.83, the Rf values are almost the same therefore the product does contain benzaldehyde. The solvent that was used is 70:30 hexane ethyl acetate. Aim The aim of this experiment is to synthesise methyl-3-phenyl-2-propenoate Introduction Wittig reaction is a reaction between a ketone or aldehyde with phosphonium ylide to form an alkane and …show more content…
Percentage yield = actual yield × 100% Theoretical yield Actual yield in moles= 0.33g/162 = 2.03×10-3mol Percentage yield = (2.03×10-3/5×10-3) × 100% =0.41% Reaction of benzaldehyde with methyl (triphenylphosphoranylidene) acetate Mechanism of a Wittig reaction Table1: Rf values for tlc with 70:30 hexane ethyl acetate sample Rf value a b Benzaldehyde 0.85 34 40 Methyl-3-phenyl-2-propenoate 0.83 33.2 40 B P Figure1: TLC plate of benzaldehyde and methyl-3-phenyl-2-propenoate Key: B= Benzaldehyde P= Methyl-3-phenyl-2-propenoate
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This week’s lab was the third and final step in a multi-step synthesis reaction. The starting material of this week was benzil and 1,3- diphenylacetone was added along with a strong base, KOH, to form the product tetraphenylcyclopentadienone. The product was confirmed to be tetraphenylcyclopentadienone based of the color of the product, the IR spectrum, and the mechanism of the reaction. The product of the reaction was a dark purple/black color, which corresponds to literature colors of tetraphenylcyclopentadienone. The tetraphenylcyclopentadienone product was a deep purple/black because of its absorption of all light wavelengths. The conjugated aromatic rings in the product create a delocalized pi electron system and the electrons are excited
The spots moved 3.8cm, 2.3cm, 2.1cm, 1.8cm, and 2.5 cm, for the methyl benzoate, crude product, mother liquor, recrystallized product, and isomeric mixture, respectively. The Rf values were determined to be.475,.2875,.2625,.225, and.3125, for the methyl benzoate, crude product, mother liquor, recrystallized product, and isomeric mixture, respectively. Electron releasing groups (ERG) activate electrophilic substitution, and make the ortho and para positions negative, and are called ortho para directors. In these reactions, the ortho and para products will be created in a much greater abundance. Electron Withdrawing groups (EWG) make the ortho and para positions positive.
2-ethyl-1,3-hexanediol. The molecular weight of this compound is 146.2g/mol. It is converted into 2-ethyl-1-hydroxyhexan-3-one. This compounds molecular weight is 144.2g/mol. This gives a theoretical yield of .63 grams. My actual yield was .42 grams. Therefore, my percent yield was 67%. This was one of my highest yields yet. I felt that this was a good yield because part of this experiment is an equilibrium reaction. Hypochlorite must be used in excess to push the reaction to the right. Also, there were better ways to do this experiment where higher yields could have been produced. For example PCC could have been used. However, because of its toxic properties, its use is restricted. The purpose of this experiment was to determine which of the 3 compounds was formed from the starting material. The third compound was the oxidation of both alcohols. This could not have been my product because of the results of my IR. I had a broad large absorption is the range of 3200 to 3500 wavenumbers. This indicates the presence of an alcohol. If my compound had been fully oxidized then there would be no such alcohol present. Also, because of my IR, I know that my compound was one of the other 2 compounds because of the strong sharp absorption at 1705 wavenumbers. This indicates the presence of a carbonyl. Also, my 2,4-DNP test was positive. Therefore I had to prove which of the two compounds my final product was. The first was the oxidation of the primary alcohol, forming an aldehyde and a secondary alcohol. This could not have been my product because the Tollen’s test. My test was negative indicating no such aldehyde. Also, the textbook states that aldehydes show 2 characteristic absorption’s in the range of 2720-2820 wavenumbers. No such absorption’s were present in my sample. Therefore my final product was the oxidation of the secondary alcohol. My final product had a primary alcohol and a secondary ketone
Wittig reactions allow the generation of an alkene from the reaction between an aldehyde/ketone and an alkyl halide (derived from phosphonium salt).The mechanism for the synthesis of trans-9-(2-phenylethenyl) anthracene first requires the formation of the phosphonium salt by the addition of triphenylphosphine and alkyl halide. The phosphonium halide is produced through the nucleophilic substitution of 1° and 2° alkyl halides and triphenylphosphine (the nucleophile and weak base). An example is benzyltriphenylphosphonium chloride, which was used in this experiment. The second step in the formation of the of the Wittig reagent, which is primarily called a ylide and derived from a phosphonium halide. In the formation of the ylide, the phosphonium ion in benzyltriphenylphosphonium chloride is deprotonated by the base, sodium hydroxide to produce the ylide as shown in equation 1.
The goal of this lab is to exemplify a standard method for making alkyne groups in two main steps: adding bromine to alkene groups, and followed by heating the product with a strong base to eliminate H and Br from C. Then, in order to purify the product obtained, recrystallization method is used with ethanol and water. Lastly, the melting point and IR spectrum are used to determine the purity of diphenylacetylene.
The percent yield of products that was calculated for this reaction was about 81.2%, fairly less pure than the previous product but still decently pure. A carbon NMR and H NMR were produced and used to identify the inequivalent carbons and hydrogens of the product. There were 9 constitutionally inequivalent carbons and potentially 4,5, or 6 constitutionally inequivalent hydrogens. On the H NMR there are 5 peaks, but at a closer inspection of the product, it seems there is only 4 constitutionally inequivalent hydrogens because of the symmetry held by the product and of this H’s. However, expansion of the peaks around the aromatic region on the NMR show 3 peaks, which was suppose to be only 2 peaks. In between the peaks is a peak from the solvent, xylene, that was used, which may account to for this discrepancy in the NMR. Furthermore, the product may have not been fully dissolved or was contaminated, leading to distortion (a splitting) of the peaks. The 2 peaks further down the spectrum were distinguished from two H’s, HF and HE, based off of shielding affects. The HF was closer to the O, so it experienced more of an up field shift than HE. On the C NMR, there are 9 constitutionally inequivalent carbons. A CNMR Peak Position for Typical Functional Group table was consulted to assign the carbons to their corresponding peaks. The carbonyl carbon, C1, is the farthest up field, while the carbons on the benzene ring are in the 120-140 ppm region. The sp3 hybridized carbon, C2 and C3, are the lowest on the spectrum. This reaction verifies the statement, ”Measurements have shown that while naphthalene and benzene both are considered especially stable due to their aromaticity, benzene is significantly more stable than naphthalene.” As seen in the reaction, the benzene ring is left untouched and only the naphthalene is involved in the reaction with maleic
Brandon Meas Block: B Day 4 Lab day 1 5/12/17 Lab day 2 5/23/17 Lab Day 3 6/2/17 Lab 9: Acids and Bases Purpose: The purpose of the lab is to calculate the concentration of a known acid. Using the data collected from this lab, you will calculate the molarity of the acid. Introduction:
The unknown bacterium that was handed out by the professor labeled “E19” was an irregular and raised shaped bacteria with a smooth texture and it had a white creamy color. The slant growth pattern was filiform and there was a turbid growth in the broth. After all the tests were complete and the results were compared the unknown bacterium was defined as Shigella sonnei. The results that narrowed it down the most were the gram stain, the lactose fermentation test, the citrate utilization test and the indole test. The results for each of the tests performed are listed in Table 1.1 below.
The overall objective of this experiment was to perform a Wittig reaction from creating an ylide and mixing it with a carbonyl (C=O) compound, cinnamaldehyde. The completion of the reaction was confirmed ultimately from the initial TLC analysis. Since TLC separates the components of the spotted material, as long as the retention factor values were different for cinnamaldehyde, the starting reagent, and the product(s), it was evident that some of the reaction had gone to completion. However, as seen in Figure 3, there was some blurred area between the product spots. This indicated that there still existed some impurities, most likely the starting reagent, which was affecting the movement of the compounds through the solvent, petroleum
Discussion: E-stilbene is a molecule molecule consisting of carbon-carbon double bond with a phenyl functional group attached to each carbon on opposite sides of the double bond. Thus, since this molecule is an alkene, the electrophilic addition of bromine causes the bromine to break and add to the carbon carbon double bond. This mechanism essentially can be considered to have two routes, but three different products. One route will use from a three membered ring (cyclic) with a bromine cation, which will in turn from a meso product (Meso-stilbene dibromide) due to the Sn2 (2nd order bimolecular) addition of bromine, as bromine can only attack the carbon from the opposite side. The meso product has a 1R 2S configuration at its stereoisomers.
After observing that all of our test results were positive, we knew that in our compound unsaturation was present, there were primary or secondary alcohols, methyl ketones, and an aldehyde. Keeping this in the back of our minds, we grabbed the derivatives and tested the melting points of each. When determining the melting point of the 2,4-dinitrophenylhydrazone derivative, we observed it to be exactly at 106°C. With this in mind, we also tested the melting point of our semicarbazone derivative, which turned out to be around ~101°C. After obtaining these numbers, we took a look at the Table J.1 and found the numbers that matched up best with our IR results, various tests, and melting point results. We determined that our Unknown sample A was actually Octanal; the structure of which is drawn
Organic compounds are commonly found every day in every part of life. Propionaldehyde is a common organic compound also known as propanal, propaldehyde, and methylacetaldehyde with propanal being the most common alternate name. It is a clear colorless liquid at room temperature. Coming from the functional group of aldehyde, propionaldehyde has a C=O bond in replace with two hydrogen atoms, which would be the base propane molecule. The molecular formula is C3H6O, the structural formula CH3CH2CHO, the structure is found in figure 1 (end). Propionaldehyde can only be produced in few ways by a few companies and is used in many various products. There are many few specifically know health effects of propionaldehyde, but it is a very dangerous compound due to its chemical properties.
The majority of the chemical reactions associated with diphenyl ether relate to the structures of the two phenyl rings of the organic compound due to the lack of reactivity typically associated with ethers. Ethers usually make excellent solvents due to the characteristic lack of reactivity. However, diphenyl ether participates in interesting reactions in spite of the stereotype. First and foremost, the formation of diphenyl ether primarily results from a deviation of Williamson Ether synthesis. These general reactions “involve an alkoxide that reacts with a primary haloalkane or a ...