The objective of this experiment was to produce a compound that had additional carbons in its structure. The Grignard reaction is one such reaction where additional carbons can be added to molecules. In this lab, benzophenone and bromobenzene were used to synthesize triphenylmethanol by means of a Grignard reaction. A reflux reaction was undertaken to produce the Grignard reagent. Recrystallization was then used to get a product free from contamination. IR peaks were at ???? cm- and ???? cm-. The product had a melting point at ????-???? °C. The percent yield was ??? %. Mechanism The objective of this experiment was to produce triphenylmethanol using benzophenone and bromobenzene. The first step involved a Grignard reaction where magnesium was added to bromobenzene in the presence of ether to produce phenylmagnesium bromide (the Grignard reagent). This was then added to benzophenone where it reacted with the electrophilic carbonyl …show more content…
The low yield could be attributed to the multiple intermediate steps which could have contributed to some of the loss of the product. Also, in spite of taking all precautions possible, some procedures may have not been conducted as precisely as needed. In addition, there may be some problems associated with the lapse of time between the preparation of the Grignard reagent and the second reaction where triphenylmethanol is produced. It is desirable to conduct both the reactions on the same day. Furthermore, a major cause of the low yield could be the moisture present in the air, because water acts as an acid. Even acid from a finger-print could have adversely impacted the process. Even though the equipment was subjected to flame drying, some moisture could have been left in the equipment causing the low yield. Contaminants in the process could also have potentially caused a lower
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
In a separate beaker, acetone (0.587 mL, 8 mmol) and benzaldehyde (1.63 mL, 16 mmol) were charged with a stir bar and stirred on a magnetic stirrer. The beaker mixture was slowly added to the Erlenmeyer flask and stirred at room temperature for 30 minutes. Every 10 minutes, a small amount of the reaction mixture was spotted on a TLC plate, with an eluent mixture of ethyl acetate (2 mL) and hexanes (8 mL), to monitor the decrease in benzaldehyde via a UV light. When the reaction was complete, it was chilled in an ice bath until the product precipitated, which was then vacuum filtrated. The filter cake was washed with ice-cold 95% ethanol (2 x 10 mL) and 4% acetic acid in 95% ethanol (10 mL). The solid was fluffed and vacuum filtrated for about 15 minutes. The 0.688 g (2.9 mmol, 36.8%, 111.3-112.8 °C) product was analyzed via FTIR and 1H NMR spectroscopies, and the melting point was obtained via
Triphenylmethyl Bromide. A 400 mL beaker was filled with hot water from the tap. Acetic acid (4 mL) and solid triphenylmethanol (0.199 g, 0.764 mmol) were added to a reaction tube, with 33% hydrobromic acid solution (0.6 mL) being added dropwise via syringe. The compound in the tube then took on a light yellow color. The tube was then placed in the beaker and heated for 5 minutes. After the allotted time, the tube was removed from the hot water bath and allowed to cool to room temperature. In the meantime, an ice bath was made utilizing the 600 mL plastic beaker, which the tube was then placed in for 10 minutes. The compound was then vacuum filtered with the crystals rinsed with water and a small amount of hexane. The crude product was then weighed and recrystallized with hexane to form fine white crystals, which was triphenylmethyl bromide (0.105 g, 0.325 mmol, 42.5%). A Beilstein test was conducted, and the crystals produced a green to greenish-blue flame.
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.
Results: Through a melting point reading, it was determined that the product obtained was 2,4-Dibromoanisol mp 55-58 C. The products obtained by my partners, were determined to be: (p-bromoacetanilide mp 160-165 C) and (2,4,6 tribromoaniline, mp of 108-110 C) respectively.
The presence of the strong peak at 1602 cm-1 supports the claim that there is an aromatic ring located in the product. Another piece of evidence to support the E1cB reaction step is the presence of the strong alkene C=C stretch (conj) located at 1628.2 ppm which supports the claim of the combination of the two reagents. Methoxy is represented in the product through the two peaks located at 1655.2 cm-1 and 1278.7cm-1 which shows that the Ketone C=O stretch (conj) and ether C-O stretch are located in the final product. Chloro is found in the product through the chlorine displayed as an alkyl halide C-Cl stretch in the product through the peak at 675.8
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.
Then the reaction tube was capped but not tightly. The tube then was placed in a sand bath reflux to heat it until a brown color was formed. Then the tube was taken out of the sand bath and allowed to cool to room temperature. Then the tube was shaken until a formation of a white solid at the bottom of the tube. After formation of the white solid, diphenyl ether (2 mL) was added to the solution and heated until the white solid was completely dissolved in the solution. After heating, the tube was cooled to room temperature. Then toluene (2 mL) was added to the solution. The tube was then placed in an ice bath. Then the solution was filtered via vacuum filtration, and there was a formation of a white solid. Then the product was dried and weighed. The Final product was hexaphenylbenzene (0.094 g, 0.176 mmol,
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.
Thickett, Geoffrey. Chemistry 2: HSC course. N/A ed. Vol. 1. Milton: John Wiley & Sons Australia, 2006. 94-108. 1 vols. Print.
After performing the first Gas Chromatography, we took the organic layer, and mixed it with saturated Sodium Hydroxide. We performed this step to remove the (-OH) group from the Eugenol. The purpose was to make the water as a product, which can also be used as a solvent for the Eugenol that was ionized, for the two substances Acetyl Eugenol and Beta Caryophyllene. Again, we see the density differences in the solvents; we were able to take the organic layer. Finally, we transferred the layer into the beaker and dried, to perform the Gas Chromatography
In the primary reduction of m-acetophenone with tin and hydrochloric acid to yield 3-aminoacetophenone, there had to be some experimental precautions taken in order for the reduction to take place. For instance, granular tin was used instead of a single plate of tin because granular particles have more surface area for the reaction to take place on. More surface area means that there is more space for the reaction to occur so it happens more efficiently. Additionally, hydrochloric acid was added slowly to the reaction mixture. This is because the addition of HCl to the reaction mixture of m-acetophenone and tin causes an exothermic reaction that foams and produces hydrogen gas. Hydrogen gas in the presence of heat will explode, so adding the
The organic layer remaining in the receiving flask was dried by adding to it 0.1-0.2g of anhydrous magnesium