The Characteristics of Freidel-Crafts reactions in the synthesis of bexarotene Lily C. Draga March 12 2023 Miami University Abstract The purpose of this experiment was to learn about Friedel-Crafts alkylations, acylations, and to perform the second step in the synthesis of bexarotene. The final, purified product had a percent yield of 22.44% and a Rfvalue of .69 which matched the provided standard. Peaks in the IR spectrum like the peak at 3018 cm-1 and another peak at 1384 cm-1represented groups known to be on the desired product. It can be drawn from this research that product 3 (1,1,4,4,6-Pentamethyl-1,2,3,4-tetrahydronaphthalene) was successfully synthesized from this reaction. Introduction The purpose of this experiment was to learn about Friedel-Crafts alkylations, acylations, and perform the second step in the synthesis of bexarotene. Friedel-Crafts reactions are used to create carbon-carbon bonds to aromatic …show more content…
Relevant peaks of the 13C NMR spectrum of the product and their assignment. The peak at 32 represented the 4 sp3 methyl groups in sections 2 and 3. The peak at 35.3 corresponded to equivalent carbon 4 and 7 which were sp3 c-c bonds. The peak around 34 corresponds with carbons 5 and 6. The peaks at 126, 134, 141, and 144 all correspond to the different aromatic carbons, and the peak around 21 ppm represents the ethyl group at point 1 coming off of the ring. Discussion The desired product that was aimed to be synthesized in this reaction was successfully synthesized. This is supported by multiple peaks from the IR spectrum. Peak 3018 represents the aromatic benzene and another peak at 1384 represents the Sp3 carbon-carbon bonds. It is also supported by 13C NMR and 1H NMR data. The purification of the synthesized product was successful as well. This is supported by the final TLC plate synthesized after the product was purified. (Image 2). Image 2. The TLC plate comparing the standard (left) and purified compound (right), with
During the Bromine test, the bromine transformed from brown to clear indicating the presence of an alkene. Also during the permanganate test, the compound changed from purple to brown. This also indicates the presence of an alkene, which indicates the E2 reaction did occur. These two positive test allowed for a GC spectrum to be obtained, if the IR confirmed there was no water in the final compound. The IR spectrum obtained, did contain a peak at 3388 cm-1, indicating an alcohol group present, but the degree of the peak was so small that a GC spectrum could be obtained.
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.
Introduction The experiments in this lab each involved a Diels-Alder reaction. A Diels-Alder reaction is a one-step reaction between a conjugated diene and a dienophile. The Diels-Alder reaction is exothermic. In the reaction, the bonding electrons rotate to form carbon-carbon bonds which then create a cyclohexane ring product.
TLC works based on different molecules travelling different speeds up a TLC plate based on polarity. TLC can be used to identify molecules and check purity. Since the three active components in Excedrin have different polarities, TLC was useful in identifying our samples based on how fast they ran up the TLC plate. We applied TLC by co-spotting our samples with the stock-room version of what believed them to be to see if they travelled the same distance up the plate. This application of TLC was useful because it allowed us to conclude the active component of Excedrin in each of our crystals.
In 1997, Howarth and his group80 reported first, the asymmetric Diels-Alder reaction by using dialkylimidazolium salts (chiral and achiral) as efficient organocatalyst between crotonaldehyde or methacrolein and cyclopentadiene. The enentiomeric excess was less than 5% and no such diastereoselectivity were observed. Here enantiomeric excess did not depends upon the ionic liquids chirality, both chiral CILs and achiral CILs gave the near about same results. After that time researchers have been tried to design and synthesized Lewis acid based
The purpose of this experiment was to identify the unknown alkyl bromide and ketone using a Grignard reaction and IR spectrum. Also, retrosynthesis analysis was used to determine the success of identifying starting material. The organometallic compounds have a carbon-metal bond that is used to create alcohol and to expand chains of carbons. Grignard reagents, a part of organometallic ionic compounds, are widely used in organic synthesis because they are considered strong base, strong base carbon nucleophile, and soluble in many organic solvents. Results: Alkyl bromide #24 and alkyl ketone
The last TLC indicated there were compounds present, which
Table 1: IR Spectra of Cyclohexanol Expected Peaks Functional Group Observed Peaks Functional Group 3600- 3200 cm-1 O-H 1500-1200 cm -1 3000- 2850 cm-1 C-C Alkane 1500-1000 cm-1 C-C Alkane Table 2: IR Spectra of Synthesized Cyclohexanone Expected Peaks Functional Group Observed Peaks Functional Group 1810-1640 cm-1 C = O 1500- 1100 cm-1 C
The reaction was allowed to proceed for 30 minutes and was subsequently quenched using hydrochloric acid. The addition of hydrochloric acid permitted the protonation of the reduced ketone (O-) to form the two diastereomer
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 bromine test yielded a positive result; each brown drop of the bromine reagent added disappeared in the solution. The positive result indicates the presence of an alkene. The IR spectrum collected corresponds greatly to the sample spectrum of cyclohexene. The peak at 3023.01indicates a sp2 C-H group, the peaks at 2924.79 and 2859.53 indicates a sp3 C-H, and the peak at 1653.31 indicates a carbon-carbon double bond. Furthermore, the absence of a peak at 3322.01 shows that there is not an alcohol group in the product, meaning that the product did not contain any
The obtained solid was filtered, dried and recrystallized using ethanol to get the compound 1,3-benzoxazole-2-thiol 1. The different derivatives of 1,3-benzoxazole-2-thiol were synthesized by similar method by using various 2-amino phenols. Colour: white; IR (KBr, cm-1): 3386 cm-1 (-SH); 1H NMR (DMSO-d6, δ ppm): 7.3(s, H Ar-H),6.9(dd, H Ar-H),
1.3. An Overview for the Synthesis of Tetrahydropyrans, Piperidines and Dihydro-γ-pyrone Derivatives To build this class of heterocycles, many strategies have been developed over the years. The most widely used methods are the Prins cyclization, hetero-Diels–Alder (HDA) cyclization, oxonium-ene cyclization, the intramolecular Michael additions and ring-closing metathesis. Other strategies include electrophile-induced cyclizations of non-activated alkenes and Lewis acid promoted cyclizations of epoxy alcohols/amines.
3. To purify and identify the product, recrystallization is used in order to purify the product, then melting point and TLC techniques are used to identify the product. Theory 4.
Other expected peaks at 1583.02 cm-1 (aromatic C-C) and 1016.21 cm-1 (C-O alcohol) are also seen and there are no outlying peaks that would suggest other products as well. From the 1H NMR spectra for 2-nitrophenol, a very similar result is observed. We see multiple peaks in the 8.0-6.5 PPM region suggesting the aromatic ring and the correct 8.2 (d, 0.80 H), 7.6 (dd, 0.78 H), and 7.1 (m, 2.00 H) peaks for the ortho substituted product. We also see a very strong outlying peak at 10.6 (s, 0.87 H) representing the alcohol hydrogen in the nitrophenol along with no other strong outlying peaks except for the 2.1 PPM acetone peak.