Title of experiment: The Sandmeyer Reaction: 2-iodobenzoic Acid Aim: • To carry out the sandmeyer reaction. • To calculate the % yield • To isolate and purify the solution Introduction: The Sandmeyer reaction is a versatile means of replacing the amine group of a primary aromatic amine with a number of different substituents. The diazonium salt is formed by the reaction of nitrous acid with the amine in acid solution. Nitrous acid is not stable and must be prepared in situ; in strong acid it dissociates to form nitroso ions, +NO, which attack the nitrogen of the amine. The intermediate so formed loses a proton, rearranges, and finally loses water to form the resonance-stabilized diazonium ion. The diazonium ion is reasonably stable in aqueous solution at 0°C; on warming up it will form the phenol. A versatile functional group, it will undergo all the reactions depicted there as well as couple to aromatic rings activated with substituents such as amino and hydroxyl groups to form the huge class of azo dyes. Diazonium salts are not ordinarily isolated …show more content…
This reaction is carried out at low temperatures because the diazonium salt is stable at low temperatures. At low temperatures the system is stable and the molecular movement is quite low. Potassium iodide and water is added and the mixture separates, the mixture is put on a hot plate and heated to 40ᵒ once the mixture has reached this temperature a vigorous reaction occurs, gas evolution (purple gas) and the separation of the tan solids take place, this happens because once the gas is let out the carbon receives a plus charge given from the electron which turns in to a free radial which is more stable than a plus charge. When this reaction completes the chorine and the free radical combine. Potassium iodide works as a facilitator for this
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
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
Luminol can be synthesized by reaction 3-nitrophthalic acid with hydrazine to form 3-nitrophthalhydrazide. This compound is then reacted with sodium hydrosulfite to form luminol. To exhibit its chemiluminescence, luminol is reacted with an oxidizing agent which pushes electrons up to a higher energy excited state. When the electron drops back down to the lower energy ground state,
Discussion and Conclusions: Interpreting these results have concluded that relative reactivity of these three anilines in order of most reactive to least reactive go; Aniline > Anisole > Acetanilide. Aniline, has an NH2 , the most active substituent , and adds to any ortho/para position available on the ring. This data is confirmed with the product obtained, (2,4,6 tribromoaniline, mp of 108-110 C). As for anisole, it has a strongly activating group attached, OMe an alkoxy group, and it added in two of the three available spots, both ortho. The results conclude: (2,4-Dibromoanisol mp 55-58 C ). Acetanilide has a strong activating group attached, acylamino group, but this group is large and the ortho positions are somewhat hindered so the majority of the product obtained added at the para position, results conclude: (p-bromoacetanilide mp 160-165 C). Since all the substituents attached to the aromatic rings were activators the only products able to be obtained were ortho/para products.
The article, “Asymmetric one-pot Robinson annulations” (Rajagopal et al., 2001) describes the procedure of a Robinson Annulation Reaction that converts a five-membered cyclic ketone to a two-ring, bicyclic compound. In this reaction, 1.12 g of 0.01 mol dione was added to a solution of 1.15 g of 0.01 mol S-proline in dry DMSO and mixed in a beaker, followed by 0.7 g of 0.01 mol methyl vinyl ketone. This mixture was stirred for 145 ...
The three butene products have been verified to elute in the following order: 1-butene, trans-2-butene, and cis-2-butene. Theory: The dehydration of 2-butanol, a secondary alcohol, progresses readily in the presence of a strong acid like concentrated sulfuric acid (H2SO4). The reaction is completed via the E1 mechanism. Initially, the hydroxyl group is a poor leaving group, but that is remedied by its protonation by the acid catalyst (H2SO4) converting it to a better leaving group, H2O. The loss of this water molecule results in a secondary carbocation intermediate that continues to form an alkene in an E1 elimination.
Greta Christina eloquently puts into words something I know in theory, but can be hard to understand in practice in heterosexual relationships. In Are we having sex now or what? Christina details her record keeping of how many people she had sex with, and what she counted as sex. She talks about the limiting misconception of sex only being coitus, and other acts not “counting.” Christina writes of how when she started having sex with women her outdated system of what was sex and what was not sex was completely destroyed. By limiting sex to “penis in vagina,” Christina was discounting some of her favorite sexual experiances, and including ones she did not particularly enjoy.
The theoretical yield of the m-nitrobenzoate was de-termined to be 4.59 grams. 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 was 8 centimeters.
the resulting amino acid would be sodium glycinate (see fig. 3), an example of a
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%).
This experiment synthesized luminol (5-Amino-2,3-dihydro-1,4-phthalazinedione) and used the product to observe how chemiluminescence would work. The starting material was 5-nitro-2,3-dihydrophthalazine-1,4-dione, which was, after addition of reaction agents, refluxed and vacuum filtered to retrieve luminol. Using two stock solutions, we missed our precipitated luminol with sodium hydroxide, potassium ferricyanide, and hydrogen peroxide, in their respective solutions, in a dark room, to observe the blue light
The aim of this experiment was to investigate the affect of the use of a catalyst and temperature on the rate of reaction while keeping all the other factors that affect the reaction rate constant.
Benzyl bromide, an unknown nucleophile and sodium hydroxide was synthesized to form a benzyl ether product. This product was purified and analyzed to find the unknown in the compound. A condenser and heat reflux was used to prevent reagents from escaping. Then the solid product was vacuum filtered.
oxaloacetate in the presence of carbon dioxide by phosphoenolpyruvate carboxylase. Oxaloacetate is then hydrogenated by malate dehydrogenase and NADH to malate and NAD+. The enzyme fumarase turns malate into fumarate
We have no gases and solids involved, therefore it is easy to deal with solutions. Similarly, the use of a catalyst complicates things, and if used incorrectly could alter the outcome of the experiment. The theory behind this experiment is that increasing the concentration can increase the rate of the reaction by increasing the rate of molecular collisions. GRAPH I will place the reaction mixture on a paper with a black cross drawn on it. When the cross is completely obscured, the reaction will be finished.