The objective of the experiment completed was to form the product 9,10-dihydroanthracene-9,10-α,β-succinic anhydride from anthracene and maleic anhydride. The reaction that took place is named a Diels-Alder reaction, defined as an addition reaction in which a diene unites with a double or triple bond of an unsaturated compound to form a 6-membered-ring. The following reactions below depict the ways in which dienes and dienophiles join to form products. Anthracene functioned as a diene and maleic anhydride functioned as the dienophile. Xylene was used as a solvent that provided a quicker way of reaction between the two starting materials. The Diels-Alder reaction is stereospecific with respect to both the diene and the dienophile. A cis-dienophile gives cis-substituents in the product and a trans-dienophile gives trans-substituents. If the diene substituents have the same stereochemistry, the diene substituents would be on the same face of the product. If the diene substituents have opposite stereochemistry, the diene substituents would be on opposite faces of the product. The limiting reagent in the case of the experiment was the maleic anhydride. The …show more content…
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
The Diels-Alder reaction, an electrocyclic reaction between a conjugated diene and a substituted alkene, also known as a dienophile, was used in the experiment. The purpose was to synthesize a substituted cyclohexene derivate by the reaction between the diene and dienophile, and it reacted in a reflux solution with toluene as the solvent forming an unsaturated six-membered ring. First, approximately 54 mg each of both compounds, tetraphenylcyclopentadienone (TPCPD) and diphenylacetylene (DPA), were placed in a reaction tube to be mixed and heated on a sand bath for several minutes. During the heating process, the color of the TPCPD reactant would fade as the color went from purple to white showing the other reactant. Also during the heating, DPA refluxed for a brief time until the tube was removed from the sand bath for the melted product to cool and solidify.
The goal of the experiment is to synthesize a bromohexane compound from 1-hexene and HBr(aq) under reflux conditions and use the silver nitrate and sodium iodide tests to determine if the product is a primary or secondary hydrocarbon. The heterogeneous reaction mixture contains 1-hexene, 48% HBr(aq), and tetrabutylammonium bromide and was heated to under reflux conditions. Heating under reflux means that the reaction mixture is heated at its boiling point so that the reaction can proceed at a faster rate. The attached reflux condenser allows volatile substances to return to the reaction flask so that no material is lost. Since alkenes are immiscible with concentrated HBr, tetrabutylammonium bromide is used as a phase-transfer catalyst.
Benzyne Formation and the Diels-Alder Reaction Preparation of 1,2,3,4 Tetraphenylnaphthalene Aubree Edwards Purpose: 1,2,3,4-tetraphenylnaphthalene is prepared by first producing benzyne via the unstable diazonium salt. Then tetraphenylcyclopentadienone and benzyne undergo a diels-alder reaction to create 1,2,3,4-tetraphenylnaphthalene. Reactions: Procedure: The reaction mixture was created. Tetraphenylcyclopentadienone (0.1197g, 0.3113 mmol) a black solid powder, anthranilic acid ( 0.0482g, 0.3516 mmol) a yellowish sand, and 1,2-dimethoxyethane (1.2 ml) was added to a 5-ml conical vial.
The product obtained was (2S, 3R)-2, 3-dibromo-3-phenylpropanoic acid and (2R, 3S)-2, 3-dibromo-3-phenylpropanoic acid, which are enantiomers. This was determined through melting point analysis. The melting point range for the product was 198 to 202 degrees Celsius, which is a lot close to the given melting point of the anti-addition product, 202-204 degrees Celsius. The given melting point range was 93.5-95 degrees Celsius. Furthermore, the syn-addition product is unlikely and difficult to produce due to stereochemistry selectivity.
Elijah Brycth B. Jarlos IX-Argon 1. Multicellularity is a condition of an organism to have multicellular cells. An example of a organism who has multicellular cells are plants, animals, and humans. The main reason of why scientists have a hard time finding a good set of existing organisms to compare. Is neither the first set of organisms which is being compared is dying as fast as the second specimen is being examined or they just can’t find the right species.
Dr. Condeiu’s presentation on synthetic organic chemistry was a rewarding experience because he touched on some very important concepts. Not only did he mention many of the things discussed in class in terms of real world examples, but he also brought a human face to being a synthetic organic chemist, and also mentioned several examples of synthetic challenges he has personally faced. Dr. Condeiu showed some real life examples of themes we discussed in class. In particular, I found his example of how stereochemistry is preserved during the hydrolysis of nerve agents intriguing. I also found it interesting that Phosphorus-Oxygen double bonds are common in nerve agents.
Tertiary alkyl halides tend to give a mixture with both inverted and retained configurations at reaction centers. This is because this reaction proceeds through a stable carbocation intermediate and the carbon at the reaction center goes to sp2 hybridized state (planar geometry). The incoming nucleophile can attack from both sides of the plane and can give two products with retained and inverted configuration. If there is a partial interaction with the leaving group (nucleofuge) with carbocation there will be more product with inverted configuration and if there is no interaction with leaving group racemic mixture can be obtained. The rate of the reaction depends on the formation of a carbocation (which is the slow step) and there is one molecule
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).
Experiment 2 Report Scaffold (Substitution Reactions, Purification, and Identification) Purpose/Introduction 1. A Sn2 reaction was conducted; this involved benzyl bromide, sodium hydroxide, an unknown compound and ethanol through reflux technique, mel-temp recordings, recrystallization, and analysis of TLC plates. 2. There was one unknown compound in the reaction that was later discovered after a series of techniques described above.
One of the most used methods for the formation of six-membered rings is using the reactions of 1,3-diene with an alkene. The Diels-Alder reaction is a unique reaction in organic chemistry because it is a cycloaddition reaction. The Diels-Alder reactions are also known as 1,4 addition reactions due to the formation of new carbon-carbon σ bonds and π bonds. Electron-withdrawing groups like cyano (C≡N) and carbonyl (C=O) to increase the reaction rates and reaction yields (1). Often times there are no side reactions that occur during the Diels-Alder reactions.
This verified the formation of the major products. Overall, one can say that the experiment was
Introduction The purpose of this experiment was to purify acetanilide that was contaminated with relatively small amounts of impurities using recrystallization. The success of recrystallization was dependent on a suitable solvent being chosen and proper recrystallization technique being carried out. The solvent chosen had to have a different polarity than that of the molecule of interest. The technique used was dependent on the solubility of the solvent at higher temperature and the solubility of the impurities at all temperatures.
In addition, the number of cross-linking reactions may be take place, mainly depends on the reaction conditions such as temperature, catalysts, the structure of the alcohols, amines and isocyanates. Commonly used some isocyanates structures are shown in figure 1.2 that is toluenediisocyanate (TDI),
Abstract The unknown concentration of benzoic acid used when titrated with standardized 0.1031M NaOH and the solubility was calculated at two different temperatures (20◦C and 30◦C). With the aid of the Van’t Hoff equation, the enthalpy of solution of benzoic acid at those temperatures was determined as 10.82 KJ. This compares well with the value of 10.27KJ found in the literature.