A multistep synthesis procedure was used to synthesize benzocaine from p-toluidine (Scheme 1). In step one, p-toluidine was acetylated to produce p-acetotoluidide to protect the amine from oxidation. In step two, the methyl substituent on p-acetotoluidide was oxidized to produce p-acetamidobenzoic acid. In step three, p-acetamidobenzoic acid was hydrolyzed to remove the protecting group to produce p-aminobenzoic acid. In step four, p-aminobenzoic acid was esterified to produce benzocaine. A melting point range (Table 1) and 1H NMR spectrographs (Figures 1-4) were acquired for each product to confirm product identity at each step. The experimental melting range for each compound was within one to two degrees of the literature melting point which indicated possible contaminates. This was due to incomplete drying and/or errors during synthesis. 1H NMR spectra were acquired for each compound at 300 MHz and were provided by Dr. Kim White. The 1H NMR spectrum for each compound was analyzed below (Figures 1-4). The 1H NMR for p-acetotoluidide (Figure 1) contained five significant signals. Four of the signals were produced by p-acetotoluidide while the fifth signal (7.25 δ) was produced by the 1H NMR solvent, CDCl3. Due to proton exchange due to hydrogen bonding, there was no significant signal produced for the hydrogen bonded to the amide group. Due to this quality of hydrogen bonding the signal can manifest as broad, at the wrong chemical shift, or be absent. In this case, the signal produced by the hydrogen bonded to the amide group was absent. A list of the types of hydrogens and their chemical shifts for p-acetotoluidide was recorded (Table 2). The 1H NMR for p-acetamidobenzoic acid (Figure 2) contained five significant signa... ... middle of paper ... ...d, water (10 mL) was added and the resulting solution was neutralized to pH 7-8 by adding sodium carbonate (1.51 g, 14.2 mmol). The mixture was extracted twice with dichloromethane (two 10 mL portions). The combined organic layers were washed with water (10 mL) and sodium chloride (10 mL). The remaining organic layer was dried with anhydrous sodium sulfate. The solution was filtered and the remaining solvent was evaporated on a hot plate. Crystallization of benzocaine occurred. The crystals were recrystallized with methanol and water while heating. The reaction was cooled in an ice bath. The pale yellow precipitate was removed via vacuum filtration and dried under continuous filtration (0.17 g, 1.03 mmol). MP = 85-87 ͦC (literature value 88-90 ͦC); 1H NMR (300 MHz, CDCl3): δ 7.83-7.86 (d, 2H), 6.61-6.64 (d, 2H), 4.27-4.34 (q, 2H), 4.10 (s, 2H), 1.32-1.37 (t, 3H).
... for various anions. Reactivity reactions and quantitative analysis comparing the unknown compound and calcium nitrate verified this hypothesis. Calcium nitrate was most safely and effectively synthesized by combining solutions of calcium chloride and lead nitrate. The MSDS data showed that the compound is a strong oxidizer but is not very toxic. Besides following standard laboratory safety measures, care should also be taken to ensure the compound is not exposed to heat, shock, or incompatible materials as listed on the MSDS that may cause fire or explosion.
...e 3. Both letters A and B within the structure of trans-9-(2-phenylethenyl) anthracene, that make up the alkene, have a chemical shift between 5-6 ppm and both produce doublets because it has 1 adjacent hydrogen and according to the N + 1 rule that states the number of hydrogens in the adjacent carbon plus 1 provides the splitting pattern and the number of peaks in the split signal, which in this case is a doublet.1 Letters C and D that consist of the aromatic rings, both are multiplets, and have a chemical shift between 7-8 ppm. 1H NMR could be used to differentiate between cis and trans isomers of the product due to J-coupling. When this occurs, trans coupling will be between 11 and 19 Hz and cis coupling will be between 5 and 14 Hz, showing that cis has a slightly lowered coupling constant than trans, and therefore have their respective positions in a product. 2
Part C. Ibuprofen consists of covalently-bonded carbon, hydrogen, and oxygen atoms. Two CH3 molecules are single-bonded to a CH molecule. The CH molecule is bonded to a carbon atom that forms a 6-sided ring of carbon atoms. Another CH molecule is single-bonded to a carbon atom on the other side of the ring. There are 3 double bonds inside the rings between carbon atoms. On the right, another CH3 molecule and a COOH molecule are both single bonded to the CH molecule.
The IR spectrum RM-02-CC2 was obtained. The spectrum consisted of a carbonyl peak, an aromatic carbon-carbon double bond peak, and a sp2 hybridized carbon and hydrogen bond peak at 1713, 1598, and 734. These functional groups are all present in 9-flourenone. The carbonyl group specifically was important because fluorenone was the only that contained a carbonyl group. The Identity was further confirmed by the melting point, 79-80˚C. This value is similar to the known value 84˚C2. The melting point observed during the experiment is greater than the known because the sample is slightly impure. This impurity is caused by presence of fluorene on the tip of the columns. As stated before, the tip of the column needs to be manage to ensure pure products. The presence of fluorene would increase the temperature as seen in the melting point results because the melting point of this compound is greater than fluorenone. Overall, both compounds were separated with column chromatography and presented reasonable yields for both products. Column chromatography is a useful technique to separate mixtures with both large and small quantities. Unlike TLC, column chromatography and be used for large amounts of
The IR spectrum that was obtained of the white crystals showed several functional groups present in the molecule. The spectrum shows weak sharp peak at 2865 to 2964 cm-1, which is often associated with C-H, sp3 hybridised, stretching in the molecule, peaks in this region often represent a methyl group or CH2 groups. There are also peaks at 1369 cm-1, which is associated with CH3 stretching. There is also C=O stretching at 1767 cm-1, which is a strong peak due to the large dipole created via the large difference in electronegativity of the carbon and the oxygen atom. An anhydride C-O resonates between 1000 and 1300 cm-1 it is a at least two bands. The peak is present in the 13C NMR at 1269 and 1299 cm-1 it is of medium intensity.
barbier reaction: In a 50 mL round bottom flask that had a reflux condenser attachment, saturated ammonium chloride (5 mL), THF (1 mL), zinc powder (0.4 g), benzaldehyde (0.500 mL, 0.5225 g, 4.92 mmol), and allyl bromide (0.470 mL, 0.6533 g, 5.40 mmol) were charged with stir bar and stirred at room temperature for 45 minutes. Diethyl ether (10 mL) was added to the reaction mixture and stirred. The mixture was gravity filtered into a beaker that was topped with a watchglass. The filtrate was transferred to a separatory funnel and the organic layer was extracted with deionized water (10 mL) and diethyl ether (15 mL). The organic layer was placed into an Erlenmeyer flask and the aqueous layer was placed into a beaker, which was extracted with
Figure 2: Illustrates the NMR of the Isoborneol/Borneol. Area under curve represent ratio of % bornol vs % isoborneol
A weak peak was at a position between 1600-1620 cm-1 can also be seem in the IR, which was likely to be aromatic C=C functional group that was from two benzene rings attached to alkynes. On the other hand, the IR spectrum of the experimental diphenylacetylene resulted in 4 peaks. The first peak was strong and broad at the position of 3359.26 cm-1, which was most likely to be OH bond. The OH bond appeared in the spectrum because of the residue left from ethanol that was used to clean the product at the end of recrystallization process. It might also be from the water that was trapped in the crystal since the solution was put in ice bath during the recrystallization process. The second peak was weak, but sharp. It was at the position of 3062.93 cm-1, which indicated that C-H (sp2) was presence in the compound. The group was likely from the C-H bonds in the benzene ring attached to the alkyne. The remaining peaks were weak and at positions of 1637.48 and 1599.15 cm-1, respectively. This showed that the compound had aromatic C=C function groups, which was from the benzene rings. Overall, by looking at the functional groups presented in the compound, one can assume that the compound consisted of diphenylacetelene and ethanol or
Zhang X., Tang H., Ye C. and Liu M. (2006). Structure-based drug design: NMR-based approach for ligand-protein interactions. Drug Discovery Today: Technologies. 3 (3), pp. 241-245.
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 expected melting point of Semicarbazone of Cyclohexanone is 166°C.1 The assumed product is Semicarbazone of Cyclohexanone. Observed temperature being lower than the expected may indicate a contamination or an impurity. The low temperature result was shown to be more accurate than the room temperature result. Perhaps, in the room temperature, there was more of a mix in the products (i.e. containing both Semicarbazone of Cyclohexanone and Furaldehyde). This is reinforced by the pale yellow colour observed, when Semicarbazone of Cyclohexanone is supposed to be white. Room temperature result could be close to the eutectic point. This is kinetic control, as it is formed much quicker than the product of the high temperature reaction. To fix the problem of lower than expected melting point could be have a set temperature as to how cold the low temperature should be (e.g.
The functional groups that where identified by the proton NMR in this compound are methoxy, sulfoxide, as well as an amine functional group. The methoxy group will shift between 3.5to 4.0 ppm in the ‘H NMR. A sulfoxide group will not show in the ‘H NMR because it has no hydrogens attached to it. An amine group will indicate between 8.0-9.0ppm in the ‘HNMR meaning it is more downfield based on the groups around it.8 The peaks were applied based on the rule n+1, where n is the number of neighboring hydrogens. Methoxy is a singlet because when looking at the structure of esomeprazole magnesium, you notice that there is no neighboring hydrogen therefore showing that 0+1= 1. The parts labelled B and C are the sulfoxide and amine groups which are both doublets because they have neighboring hydrogens which averages two as 1+1=2.
7- When describing the properties of JNJ 40279486, the authors highlight the selectivity of the compound over the hERG channel. Explain wh...
The main diagnostic peaks that are related to the ligand active groups and which are expected to display marked shifts or changes after coordination with Hg(II) are summarized in Table 2. As previously reported [29, 30], thiosemicarbazide and thiourea derivatives, which contain thioamide (-NH-C=S) moiety are known to display thione–thiol tautomerism in solution. The presence of v/δ(C=S) characteristic peaks at approximately 1300, 870 cm-1, absence of v/δ(C-S) peaks at about 1150, 650 cm-1 in addition to the absence of the diagnostic (S-H) peak at 2350 cm-1 and presence of only one peak at 1660 cm-1 correspond to the triazine C=N bond, revealed that thione form is the dominant one in solid state. After coordination with Hg2+, the spectrum of the complex showed an appearance of two peaks at 1150 and 650 cm-1, which are related to both stretching and bending vibrations of C-S bond, in addition a new peak at about 1665 cm-1correspond to C=N was also observed. These observations indicated that thion- thiol transformation had been performed during coordination with Hg2+. Also, the absence of S-H characteristic peak at about 2350 cm-1, gives and evidence for the deprotonation of the thiol (S-H). Moreover, the obvious shift of the triazine C=N peak at 1630 cm-1, confirms involvement of triazine
6. Rouhi, A. M. (2003, July 28). C&EN: SCIENCE & TECHNOLOGY - Monosodium Glutamate. Retrieved March 17, 2014, from https://pubs.acs.org/cen/whatstuff/stuff/8130sci3.html