Corrected Text Slide 1: Aromatic acids Learning Objectives At the end of this class session, you will be able to know about • Preparation and properties of aromatic acids Slide 2: Introduction Aromatic carboxylic acids belong to the group of carboxylic acids. Aromatic acids are white crystalline solids that are soluble in hot water, alcohol and ether. It is partially soluble in cold water. Slide 3: Explanation Preparation of aromatic acids Teacher: Hi, students. Today we are going to learn about the preparation of aromatic acids. Aromatic carboxylic acid is a group of carboxylic acid linked directly to the benzene ring. Benzoic acid is the simplest aromatic acid. Oxidation of side-chain of benzene derivatives produces aromatic acids. Acid …show more content…
Teacher: C6H5MgBr is the formula of Grignard reagent. Let us see an animation regarding this. Animation_1_ Preparation of aromatic acids A carboxylic acid group directly linked to the benzene ring is termed as Aromatic carboxylic acids. Following figure shows some of the examples of aromatic acids: Among all the aromatic acids, benzoic acid is the simplest aromatic acid. Preparation of aromatic acids: 1) By oxidation: Aromatic acids can be obtained by the oxidation of ‘side chain’ of benzene derivatives. Side chain can be any aliphatic portion linked to benzene ring. For the process of oxidization of the ‘side chain’, acid dichromate or permanganate or alkaline, permanganate etc., can be used. Following figure shows the side chains used during oxidization to obtain aromatic acids: In the process of oxidization of Toluene, acidified KMnO4 is used. Following reactions show the process of oxidization of Toluene by acidified KMnO4: 2) Hydrolysis of phenyl cyanide: Following figure shows the procedure to obtain aromatic acid by hydrolysis of phenyl cyanide: 3) Carbonation of Grignard reagent followed by hydrolysis: Following figure shows the process of carbonation of Grignard reagent followed by
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
There are four different types of hydrocarbons each having a different homologous series (formula for carbon chain). These being an alkane (formula = CnH2n+2), alkene (formula = CnH2n), alkyne (formula = CnH2n-2), and an alkanol which has the same formulae as an alkane only that is has a hydroxide molecule which replaces one of the hydrogen atoms (refer to figure 3 and
The carbon atoms in fatty acids are numbered from the carboxyl carbon (carbon no. 1). The carbon atom adjacent to the carboxyl carbon (that is carbon no. 2, 3 & 4) are known as α, β and gamma carbon respectively and the terminal methyl carbon is known as omega.
H Bonds form between the C=0 of the Carboxylic acid group and the N-H of the amine group
Ensure gloves are worn at all times when handling strong acids and bases within the experiment of the preparation of benzocaine. 4-aminobenzoic acid (3.0g, 0.022 moles) was suspended into a dry round-bottomed flask (100cm3) followed by methylated sprits (20 cm3). Taking extra care the concentrated sulphuric acid of (3.0 cm3, 0.031 moles) was added. Immediately after the condenser was fitted on, and the components in the flask were swirled gently to mix components. It should be ensured that the reactants of the concentrated sulphuric acid and the 4-aminobenzoic acid were not clustered in the ground glass joint between the condenser itself and the flask. In order to heat the mixture to a boiling point, a heating mantle was used and then further left for gently refluxing for a constituent time of forty minutes. After the duration of the consistent forty minutes the rou...
The purpose of this lab was to perform an electro-philic aromatic substitution and determine the identity of the major product. TLC was used to detect unre-acted starting material or isomeric products present in the reaction mixture.
...icted α-methyl-2-naphthalenemethanol. Probably the most obvious clue that corresponded to this secondary alcohol was the seven integrated hydrogens within the aromatic region of 7.5-7.9 ppm. This compound was the only one that had seven hydrogens belonging to naphthalene. The other two secondary alcohols 3-methoxy-α-methylbenzyl alcohol and 4-bromo-α-methylbenzyl alcohol have only four aromatic hydrogens.
The final product was p-methoxybenzoic acid and its identity was confirmed by melting point range of 183.6 – 184.8 oC, which closely corresponds to a standard of 185 oC. (Lehman). Since the melting point range is small, it confirms the purity of the product. Since the objective of the experiment was to determine the structure of the major component
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.
As shown in Scheme 2, the consecutive oxidations of methyl group take place for p-toluic acid and 4-CBA. In order to gain terephthalic acid as the end product, the purification from impurities including 4-CBA content in crude terephthalic acid must be conducted. In purification process, the crude terephthalic acid (a solid terephthalic acid that has been undergoing centrifugation and drying) will be dissolved in hot water to reduced 4-CBA to p-toluic acid. This reduction process is through catalytic hydrogenation on palladium catalyst. Then, the purified terephthalic acid is obtained [33]. Apart AMOCO process, the other catalytic process to produce terephthalic acid by direct oxidation was widely st...
The production of synthetic detergents are an example of a standard chemical approach. If a useful substance has some undesirable properties an attempt is made to make a near copy synthetically which will perform better.
When benzoic acid paired with 1.0 M NaOH, it was observed that both compounds were soluble. Upon the addition of 6.0 M HCl into this solution, benzoic acid became insoluble. Benzoic acid was also insoluble in 1.0 M HCl. Ethyl 4-aminobenzoate was found to be insoluble in 1.0 M NaOH and soluble in 1.0 M HCl. But then, after adding 6.0 M NaOH into the test tube C (mixture of ethyl 4-aminobenzoate and 1.0 M HCl), a white powdery solid (undissolved compound) was formed. These demonstrate that both the acid and base became more soluble when they were ionized and less soluble when they were
Esters are carboxylic acid groups that have a carbonyl acid adjacent to either linkage. Esters can be made from alcohols or carboxylic acids reactions. This is that they have a –COOH group however the hydrogen in the group instead is a methyl. Benzene ring, ethyl other alkyl group. Esters come in a number of different ways and have different effects on the human body both beneficiary and some toxic.
Stearic acid is obtained from fats and oils by saponification of triglycerides using hot water.
Acids are a material that releases a proton or hydrogen ion (H+). Acids always generate an H+ whenever the solution is aqueous, which can be easily identified. On the contrary, in an aqueous solution involving bases always produce an OH- ion. There are many different ways to identify whether a substance is an acid or a base. An acid is always sour, changes litmus, conduct an electric current, react with a base to form salt and water, and whenever there is a reaction, acids helps advance an hydrogen gas with an active metal, such as the alkaline earth metals, zinc, and many more. Some well known or common acids are citric acid, which are from citrus fruits, such as oranges, lime, and lemons. Vinegar and carbonic acid (soda/soft drinks) are also some common acids. Bases are the opposite of acids. They can be identified by their bitter taste, soapy or slippery feeling, and cannot change the color of litmus. Bases can become red litmus to reverse back to the blue litmus. Similarly, acids and bases conduct an electrical current in an aqueous solution, thus they are...