Multistep Synthesis of Benzilic Acid from Benzaldehyde Cambria M. Miller March 24, 2014 Texas A&M University at Galveston, Galveston, Texas INTRODUCTION Benzilic acid (fig. 1) is a white crystalline solid often used in organic synthesis of certain pharmaceuticals and drugs (1). It is thought that benzilic acid may have success in anti-aging products. Benzilic acid is an alpha hydroxy acid and other alpha hydroxy acids have been used in the same manner (2). Figure 1. Benzilic acid structure. The purpose of this experiment was to successfully synthesize benzilic acid from benzaldehyde. Benzaldehyde is an organic molecule used to make bitter almond oil, and to synthesize many different organic compounds (3). This experiment is a multistep synthesis which means there are multiple parts that require the product of the previous step to be used as a reactant in the following step. Thus it is very critical to have high yields and accuracy at each step. Traditionally cyanide was used as a catalyst in this reaction since Von Liebig first discovered it in his research with almond oil. However, cyanide is very poisonous and harmful to health. More recently it was discovered that Vitamin B1, a coenzyme by the name of thiamine hydrochloride may be used to catalyze the benzoin condensation, which is preferable to using cyanide. This experiment will test whether thiamine can effectively catalyze the reaction (2). The experiment begins with the condensation of benzoin (eq. 1). In the presence of the thiamine catalyst, the 2 benzaldehyde molecules condense to produce benzoin when they are heated with sodium hydroxide and ethanol. Equation 1: Benzoin Condensation. The production of benzil (eq. 2) is a redox reaction. The b... ... middle of paper ... ...uced in part C using the product from part B. Another source of error was that on two different occasions recrystallization was omitted from the procedure. While this probably does not have a huge effect, crystallizing the product helps to eliminate impurities. The overall product yield for this reaction is 90.53%. Although this number seems high, indicating a very successful synthesis, it does not account for the fact that Part C began with a new sample of benzil. Had it been continued using the product from part B, the yield would be much lower. Product may have been lost through residue being left in different glassware used due to inefficient transferring as well as reactions not running to completion. The purpose of this experiment was to produce benzilic acid, not to have high yields so in that sense there was success (excluding the formation of benzil).
This week’s lab was the third and final step in a multi-step synthesis reaction. The starting material of this week was benzil and 1,3- diphenylacetone was added along with a strong base, KOH, to form the product tetraphenylcyclopentadienone. The product was confirmed to be tetraphenylcyclopentadienone based of the color of the product, the IR spectrum, and the mechanism of the reaction. The product of the reaction was a dark purple/black color, which corresponds to literature colors of tetraphenylcyclopentadienone. The tetraphenylcyclopentadienone product was a deep purple/black because of its absorption of all light wavelengths. The conjugated aromatic rings in the product create a delocalized pi electron system and the electrons are excited
The experiment was not a success, there was percent yield of 1,423%. With a percent yield that is relatively high at 1,423% did not conclude a successful experiment, because impurities added to the mass of the actual product. There were many errors in this lab due to the product being transferred on numerous occasions as well, as spillage and splattering of the solution. Overall, learning how to take one product and chemically create something else as well as how working with others effectively turned out to be a
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,
2-ethyl-1,3-hexanediol. The molecular weight of this compound is 146.2g/mol. It is converted into 2-ethyl-1-hydroxyhexan-3-one. This compounds molecular weight is 144.2g/mol. This gives a theoretical yield of .63 grams. My actual yield was .42 grams. Therefore, my percent yield was 67%. This was one of my highest yields yet. I felt that this was a good yield because part of this experiment is an equilibrium reaction. Hypochlorite must be used in excess to push the reaction to the right. Also, there were better ways to do this experiment where higher yields could have been produced. For example PCC could have been used. However, because of its toxic properties, its use is restricted. The purpose of this experiment was to determine which of the 3 compounds was formed from the starting material. The third compound was the oxidation of both alcohols. This could not have been my product because of the results of my IR. I had a broad large absorption is the range of 3200 to 3500 wavenumbers. This indicates the presence of an alcohol. If my compound had been fully oxidized then there would be no such alcohol present. Also, because of my IR, I know that my compound was one of the other 2 compounds because of the strong sharp absorption at 1705 wavenumbers. This indicates the presence of a carbonyl. Also, my 2,4-DNP test was positive. Therefore I had to prove which of the two compounds my final product was. The first was the oxidation of the primary alcohol, forming an aldehyde and a secondary alcohol. This could not have been my product because the Tollen’s test. My test was negative indicating no such aldehyde. Also, the textbook states that aldehydes show 2 characteristic absorption’s in the range of 2720-2820 wavenumbers. No such absorption’s were present in my sample. Therefore my final product was the oxidation of the secondary alcohol. My final product had a primary alcohol and a secondary ketone
In this experiment there were eight different equations used and they were, molecular equation, total ionic equation, net ionic equation, calculating the number of moles, calculating the theoretical yield and limiting reagent, calculating the mass of〖PbCrO〗_4, calculating actual yield, calculating percent yield (Lab Guide pg.83-85).
Wittig reactions allow the generation of an alkene from the reaction between an aldehyde/ketone and a ylide (derived from phosphonium salt).The mechanism for the synthesis of trans-9-(2-phenylethenyl) anthracene first requires the formation of the phosphonium salt by the addition of triphenylphosphine and alkyl halide. The phosphonium halide is produced through the nucleophilic substitution of 1° and 2° alkyl halides and triphenylphosphine (the nucleophile and weak base) 4 An example is benzyltriphenylphosphonium chloride which was used in this experiment. The second step in the formation of the of the Wittig reagent which is primarily called a ylide and derived from a phosphonium halide. In the formation of the ylide, the phosphonium ion in benzyltriphenylphosphonium chloride is deprotonated by the base, sodium hydroxide to produce the ylide as shown in equation 1. The positive charge on the phosphorus atom is a strong EWG (electron-withdrawing group), which will trigger the adjacent carbon as a weak acid 5 Very strong bases are required for deprotonation such as an alkyl lithium however in this experiment 50% sodium hydroxide was used as reiterated. Lastly, the reaction between ylide and aldehyde/ketone produces an alkene.3
Step 1: Isobutyl benzene is combined with propionyl chloride through Friedel-Crafts acylation to form 1-(4-Isobutyl-phenyl)-propan-1-one.
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.
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 percent recovery was determined to find what percent of Acetanilide was recovered during recrystallization. At the beginning of the lab, 1.612grams of Acetanilide was weighed out. The dry crystals of Acetanilide weighed 0.979grams. The calculation goes as it is written below:
What reaction was conducted in this experiment and with what reagents? Was there a reason for this reaction beyond just synthesis of product(s)? What techniques were used to purify and identify the product(s) of the reaction?
Medicinal or Pharmaceutical Chemistry is a scientific discipline at the intersection of chemistry and pharmacology involved with designing, synthesizing and developing pharmaceutical drugs. Medicinal chemistry involves the identification, syntheses and development of new chemical entities suitable for therapeutic use. The majority of the therapeutic agents are heterocyclic compounds; hence heterocyclic chemistry has become the most prolific area for drug discovery. Based upon the fact, the present investigation was planned and substantial interest has been shown in the synthesis and characterization of various substituted novel (1, 3) benzothiazole heterocyclies derivatives in search of potential drugs.
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.
The purpose of this experiment was to produce aspirin using salicylic acid and acetic acid.
Teacher: Hi, students. Today we are going to learn about the preparation of aromatic acids.