The purpose of this experiment is to perform a two step reductive amination using o-vanillin with p-toluidine to synthesize an imine derivative. In this experiment, 0.386 g of o-vanillin and 0.276 g of p-toluidine were mixed into an Erlenmeyer flask. The o-vanillin turned from a green powder to orange layer as it mixed with p-toludine, which was originally a white solid. Ethanol was added as a solvent for this reaction. Sodium borohydride was added in slow portion as the reducing agent, dissolving the precipitate into a yellowish lime solution. Glacial acetic acid and acetic anhydride were added to the mixture while refluxing, which converted the lime colored solution into a clear mixture. The flask was cooled in an ice bath and the solution …show more content…
As seen in table 1, the theoretical yield was .712 g of C_17 H_19 NO_3. The % yield of this experiment was 7.51 % of C_17 H_19 NO_3. . This low yield can be explained from a poor recrystallization technique combined with potential contamination. Throughout the experiment, the mixture changed color from green, orange, to yellowish lime, and eventually clear. These color changes indicate a chemical change, which show that a reaction had occurred. In the first step when o-vanillin and p-toludine, imine was formed. The color change from green to orange suggests that imine appears as orange colored. In the second step, the addition of sodium borohydride reduced the imine into another derivative, which was yellowish lime color. The solution turned clear when acids and anhydrides was added, which indicated the precipitate were dissolved. However, after refluxing for a while, yellow precipitates begin to form near the top of the flask. It was assumed that the remaining starting material was concentrated from a decrease volume to reappeared in solution. Nevertheless, this may have been a sign of contamination that will negatively affect the entire reaction. This observation later resulted in a yellowish
Click here to unlock this and over one million essaysShow More
3. Upon adding 20 drops of NaOH, a white precipitate was formed signifying acidic impurity. In the second NaOH mixture, about 20 drops were administered and no precipitate formed indicating that the ample is more pure than before. Data: Weight of flask = 75.10 grams Weight of the flask with solids =
Next, about 10 mL of both solutions, Red 40 and Blue 1, were added to a small beaker. The concentration of the stock solution were recorded, 52.1 ppm for Red 40 and 16.6 ppm for Blue 1. Then, using the volumetric pipette, 5 mL of each solution was transferred into a 10 mL volumetric flask, labelled either R1 or B1. Deionized water was added into the flask using a pipette until the solution level reached a line which indicated 10 mL. A cap for the flask was inserted and the flask was invented a few times to completely mix the solution. Then, the volumetric pipette was rinsed with fresh deionized water and
Conclusion: Based on the results of molarity from Trials 1, 2, and 3, it is concluded that our experimental for each trial is .410M NaOH, .410M NaOH, and .450M NaOH. The actual molarity of the NaOH concentration used was found to be 1.5M NaOH. The percent error of the results resulted in 72%. The large error may have occurred due to over titration of the NaOH, as the color of the solution in the flask was a darker pink in comparison for the needed faint pink. Discussion of Theory:
After one colored fraction of the unknown was eluted off of the column, the 20 mL beaker was switched with the vial to collect the colorless eluent until the remaining CH2Cl2 in the column reached the top of the alumina layer. The eluted colorless methylene chloride was disposed of. Acetone was carefully added to the column. The initial colorless elute was collected in the 20 mL beaker. The last colored band
Another error was that since the percent yield was over 100, there was an error in obtaining the mass of the vials because the same balance was not used. Also, the addition of the dichloromethane could have added to the mass and when calculating the percent yield, the mass of the dichloromethane was
This would be an excellent yield if it all indeed consisted of fluorenol, but given that -OH peaks were observed in the IR, and that a good yield for this reaction was around 60%, it is possible that this percent is artificially high, and that some of this yield consisted of impurities like water and methanol that had not evaporated away. Of the product that was lost, some was lost due to bad filtration technique, as some of the product was observed to have passed through the filter paper, and into the flask. Some of the product may have also clung to the vial, as the precipitate was difficult to remove from the vial in its entirety. In order to improve this yield, more care could have been taken while removing product from the vial, and during filtration, ensuring that the filter paper was sufficiently wet and no product passed through. As some error most likely occurred due to impurities, inflating the percent yield, the product could have been allowed to dry
The percent yield calculated in this experiment was 49% that indicates errors occurred during this lab. Possible sources of error could have arisen in the decantation and recrystallization of the crystals. This process in the lab was difficult and was not
In cycle one, the double displacement reaction, Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) occurred, the result of the reaction was that the reaction mixture began to bubble with the copper filling dissolving and a vapor like substance leaving the reaction. Furthermore, when water was added, the color change, from brown to a blue color pigment. Then in Cycle two, another double displacement reaction occurred, Cu(NO3)2(aq) + 2NaOH(aq) → Cu(OH)2(s) + 2NaNO3(aq), which resulted in the reaction becoming cloudy and a darker shade of blue. Following cycle two, a decomposition reaction occurred as the result of heat being administered to the mixture, thus the following reaction occurred in cycle three, Cu(OH)2(s) → CuO(s) + H2O(l). As a
Then the flask was filled the rest of the way with distilled water to the mark. Similar steps were taken for the rock solution. The rock solution from the prior lab was filtered into a volumetric flask (100mL), then 15 M NH4¬OH (8mL) was added to the flask. After that, the flask was filled to the mark with distilled water. Both flasks were then swirled to combine the solution
N-arylsulfonyl tryptophanderivatives were investigated as ligands for the reaction due to “the high π-electron-donating characterof the indole ring” (?) B-n-butyloxazaborolidine was used at 5 mol% to accelerate and control the reaction of cyclopentadiene and 2-bromoacrolein (-78 °C) in DCM. Enantioselectivity of the desired 2R adduct occurred at ca. 200:1 with a high yield. This catalyst can be used to enantioselectively produce gibberellic acid, a plant hormone, as well as the antiulcer agent, cassiol and eunicenone.
4.1 Evaluation Assumptions It was assumed that the reactants used reacted with each other completely according to their mole ratios. It was also assumed that no impurity was present in the reactants used. Another assumption was that only ascorbic acid in the bell pepper solution reacted with the triiodide ion. It was assumed that the bell pepper was completely juiced without any loss.
Properties of Roller Compacted Concrete with Pozzolan as Cement Replacement Material Introduction: Roller compacted concrete (RCC) gets its name from the heavy vibratory steel drum and rubber-tired rollers used to compact it into its final form. RCC has similar strength properties and consists of the same basic ingredients as conventional concrete_ well graded aggregates, cementitious materials, and water_ but different mixture proportions. The largest difference between RCC mixtures and conventional concrete mixtures is that RCC has a higher percentage of fine aggregates, which allows for tight packing and consolidation . RCC may be considered for applications where no-slump concrete can be transported, placed, and compacted
In test tube E, a colourless colour formed. It is because redox reaction occurred during the test. Idoine reduced into idoine ion ， which changre from brown to colourless. In test tube F, the iodine solution change from brown to purple . It is because the salt has a function of cofactor which will shorten the time for amylase to take to break down the