In this lab 2-methyl-butyn-2-ol is hydrated to 3-hydroxy-3-methyl-2-butanone. This process was preformed by using a strong acid which created an enol, and then the enol tautomerized. Due to this being a terminal alkyne, only one product will be formed. Techniques such as simple distillation, reflux, and gravity filtration were used to produce and separate the product from the mixture that it was in. When performing this lab using only one equivalent of alkyne produced a low percent of 1%. The low yield is a result of using one equivalent instead of two. The purpose of this experiment is to preform a hydration reaction and tautomerism of the alkyne formed, which in this case is 3-hydroxy-3-methyl-2-butanone. We were trying to understand how enols are produced and its conversion of tautomerism. We also wanted to understand the …show more content…
There was not necessarily an error but rather an inconvenience to why the yield was so low. This inconvenience was adding only one equivalent of alkyne to the reflux condenser. The reason for this that there was not enough 2-methyl-butyn-2-ol for the use of two equivalents as stated in the instructions, and because there was less reactant used there would naturally be less product formed. The other source of error is the spillage of some of the reaction. These results does not correlate with the ease of the reaction occurring as mentioned in the reaction scheme. The low mass and percent yield makes it appear as though the tautomerization portion of the reaction was not favorable. I say this based on my observation where there was 35 mL of distillate, which was expected with the one equivalent, but the keto-tautomer results were so low from the theoretical yield (theorictical yield: 7.65g) that it appeared that the tautomerization was not favorable which is not true because the keto-tautomer happens so rapidly due to it being the most stable
Reacting 1-butanol produced 2-trans-butene as the major product. 1-butanol produces three different products instead of the predicted one because of carbocation rearrangement. Because of the presence of a strong acid this reaction will undergo E1 Saytzeff, which produces the more substituted
The purpose for this lab was to use aluminum from a soda can to form a chemical compound known as hydrated potassium aluminum sulfate. In the lab aluminum waste were dissolved in KOH or potassium sulfide to form a complex alum. The solution was then filtered through gravity filtration to remove any solid material. 25 mLs of sulfuric acid was then added while gently boiling the solution resulting in crystals forming after cooling in an ice bath. The product was then collected and filter through vacuum filtration. Lastly, crystals were collected and weighed on a scale.
In a small reaction tube, the tetraphenylcyclopentadienone (0.110 g, 0.28 mmol) was added into the dimethyl acetylene dicarboxylate (0.1 mL) and nitrobenzene (1 mL) along with a boiling stick. The color of the mixed solution was purple. The solution was then heated to reflux until it turned into a tan color. After the color change has occurred, ethanol (3 mL) was stirred into the small reaction tube. After that, the small reaction tube was placed in an ice bath until the solid was formed at the bottom of the tube. Then, the solution with the precipitate was filtered through vacuum filtration and washed with ethanol. The precipitate then was dried and weighed. The final product was dimethyl tertraphenylpthalate (0.086 g, 0.172mmol, 61.42%).
The actual amount of crude product was determined to be 3.11 grams. The percent yield of the crude product was determined to be 67.75 %. The actual amount of pure product formed was found to be 4.38 grams. The percent yield of the pure product was determined to be 95.42%. Regarding the thin layer chromatography, the line from the solvent front is 8 centimeters.
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
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 a ylide (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) 4 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 positive charge on the phosphorus atom is a strong EWG (electron-withdrawing group), which will trigger the adjacent carbon as a weak acid 5 Very strong bases are required for deprotonation such as an alkyl lithium however in this experiment 50% sodium hydroxide was used as reiterated. Lastly, the reaction between ylide and aldehyde/ketone produces an alkene.3
I did accomplish the purpose of the lab. First, I determined the percentage of water in alum hydrate, and the percentage of water in an unknown hydrate. The results are reasonable because they are close to the example results. Second, I calculated the water of crystallization of an unknown hydrate. Furthermore, I developed the laboratory skills for analyzing a hydrate.
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 product was recrystallized to purify it and the unknown filtrate and nucleophile was determined by taking the melting points and performing TLC. Nucleophilic substitution reactions have a nucleophile (electron pair donor) and an sp3 electrophile (electron pair acceptor) with an attached leaving group. This experiment was a Williamson ether synthesis usually SN2, with an alkoxide and an alkyl halide. Conditions are favored with a strong nucleophile, good leaving group, and a polar aprotic solvent.
2-butoxyethanol, a colorless liquid with a mild odor, is used in different paints, primers, and kinds of ink, along with numerous household cleaning products commonly found, to remove substances such as grease and oils. However, the usage of 2-butoxyethanol comes with risks as well. 2-butoxyethanol’s risks outweigh the rewards of it being used.
steps to obtain pure xylose. Moreover, the yield of xylitol is only 50 % of
If Roberta W refuses all hydration, it will definitely be viewed as her committing suicide. She is refusing hydration, which will cause risk for death. I believe refusing is definitely considered an act of suicide because it's your own body and you're stopping it from living. This situation puts Dr. R in a bad position because all patients have the right to refuse the care that is giving to them, whether it is beneficial to them or not. The physician ethical duty is to be Nonmaleficence to the patient because Dr.R needs to stop Roberta from doing something that will affect her body. It is always number one responsibility for a physician to provide the best possible care for a patient. Some people who have Roberta w. Problem is trying so hard
The aqueous layer was on the bottom because it was denser than the organic layer. The aqueous layer contained the benzoic acid and the organic layer contained the naphthalene. The drying step was partially successful in the experiment because it rid the organic layer of excess water. In the end, the melting point range of the naphthalene was 55-62 °C, unlike the actual determined melting point of 80.2 °C. There is a possibility that less than needed sodium sulfate had been added to the organic layer mixture because the melting point could have been negatively affected by excess water not absorbed by the sodium sulfate. The acidification step was successful, because it allowed the Benzoic acid to precipitate out. There was a 58% yield of benzoic acid from the crude sample, and a 98% yield of naphthalene and benzoic acid, which is great as far as results go. It means enough hydrochloric acid, HCl, was added for the conjugate acid, benzoic acid, of the base, benzoate that was in the aqueous layer Erlenmeyer flask before the addition of the acid. The separation of naphthalene and benzoic acid seemed successful as far as turnout of product came. Out of the 1.00 g of crude sample started with, 0.40 g of naphthalene was recovered and 0.58 g of benzoic acid was recovered. But as far as comparing the observed Mel-temp melting points to the actual melting points, there was a big difference between the values observed and the real melting point values. The Mel-temp temperatures for benzoic acid and naphthalene were 85-95 °C and 55-62 °C, respectively. The actual values of temperature for benzoic acid and naphthalene were122.4°C and 80.2°C, respectively. This showed that the “pure” samples were still impure in some way. It seemed as though maybe not enough vacuum filtration and drying time were causations of impure samples, probably tainted by water. The crude sample Mel-temp temperature was 55-63 °C. This
The catalytic process occurs at lower temperature anf offers higher selectivity but requires frequent regeneration of the catalyst. Then, the products are cooled and introduced into a pair of separators which separate the unreacted hydrogen. The unreacted hydrogen is compressed and recycle back to the feed and reactor. The products that leaving the separators are heated before introduced into a distillation column which the toluene is separated from the stream and recycle back to the...