An easy synthesis of 5-trifluoromethylated oxazole compounds as a building block which would be able to transform into effectively useful pharmaceuticals or chemicals can be achieved to improve the practical use. In this study, we describe the new synthesis of methyl 5-trifluoromethyl-2-phenyloxazole-4-carboxylate which derived from 4-alkoxy oxazole in one-pot by utilizing Cornforth rearrangement. At this time, we took an interest in the experimental result that no precursors of rearrangement were detected in this reaction. The strategy of designing and synthesizing compounds that inhibited reclosure from nitrile ylide resulted in successful capture of unstable precursors. Introduction The methods which substitute fluorine for proton at an …show more content…
Namely, we would be able to prepare compounds (3) as precursors for Cornforth rearrangement reaction from 2-aryloxazoles (2) which are obtained by cyclization of the corresponding glycine (1). Then compounds (3) would be transformed to compounds (4) by optimization of the reaction conditions. First, 2-aryl-5-methoxyoxazoles (2) were prepared by the method of Wipf’s protocol12) from methyl N-arylcarbonyl glycine methyl esters (1) in the presence of Et3N in DCE with PPh3 and I2 at room temperature for 19-24hr. This reaction proceeded in mild condition and afforded compound (2) in 80-97% yield by column chromatography (Table 1). Subsequently, we attempted preliminary examination by choosing 5-methoxy -2-phenyl oxazole (2a) as starting material to proceed whether Friedel–Crafts reaction. Although the normal conditions which used Lewis acid such as AlCl3 or TiCl4 with TFAA in DCE did not proceed to acylation, the reaction of introducing trifluoroacetyl group at the C4-position of oxazole without Lewis acid gave substituted oxazole (4a). Contrary to our expectations, isolated oxazole had been not trifluoroacetylated derivative (3a), reaching rearrangement compound (4a) in one step.After our optimization of the acylated condition, the use of 1.3 equivalents of TFAA and THF as a solvent and condition of the temperature at 60 degrees for 22 hr led 90%
The apparatus for the addition reaction under reflux was assembled. Magnesium (1 g) was weighted on a paper, and a few pieces of magnesium were crushed in order to activate the metal surface. Then, the round bottom flask was lowered away from the condenser, and the magnesium was added to it. After that, 10 ml of anhydrous diethyl ether was added in a round bottom flask by using the syringe, and the reaction flask was heated using a heating mantle to maximize the formation of the Grignard reagent. After 10 minutes of heating the mixture, the mixture changed color from clear to yellowish, and it turned completely Reddish brown after 12 minutes.
In this lab, three unknown compounds were separated from a mixture and identified by melting point. Unknown mixture #124 has components of acid, base and neutral compound. The compounds were identified by melting point and matched up with the known melting points from a given list. In order to identify the compound it was important to separate by dissolving the mixture in an organic solvent which was not soluble in water, and then extracting the solution first with HCl, and then dilute sodium hydroxide solution. From the separation mixture, the aqueous layer were obtained and labeled as TT-1 (base), TT-2(acid) and TT-3 (neutral) in three different test tubes for later recovery.
The purpose of this experiment was to learn about the electrophilic aromatic substitution reactions that take place on benzene, and how the presence of substituents in the ring affect the orientation of the incoming electrophile. Using acetanilide, as the starting material, glacial acetic acid, sulfuric acid, and nitric acid were mixed and stirred to produce p-nitroacetanilide. In a 125 mL Erlenmeyer flask, 3.305 g of acetanilide were allowed to mix with 5.0 mL of glacial acetic acid. This mixture was warmed in a hot plate with constantly stirring at a lukewarm temperature so as to avoid excess heating. If this happens, the mixture boils and it would be necessary to start the experiment all over again.
The goal of this lab was to prepare methyl m-nitrobenzoate using electrophilic aromatic substitution using nitration. The reaction used methyl benzoate with the acid catalyst as sulfuric acid. The mechanism for the nitration using methyl benzoate is presented in Figure 1. Figure 1: Benzene can only undergo substitution reactions that are called electrophilic aromatic substitution reactions. Given that benzene rings are used commonly in the production of many organic compounds, the capability to make substitutions to benzene is critical.
Lecturer Date Introduction Theoretical Background Procedure The procedure was segmented into two categories, the reaction set up and the crude product isolation. Reaction set up The magnetic stirrer was prepared through placing it in the fume cupboard. 1 mmol of L-Phenylalanine was placed and weighed in a 5 mL conical vial.
The reaction to synthesize benzocaine was known as a Fisher esterification reaction. The Fisher esterification was reaction between alcohol and carboxylic acid in the presence of acid. The reaction was used to form an ester. In the experiment, sulfuric acid acted as a catalyst and necessary for this reaction to occur. There was a change between the –OH group of carboxylic acid to an –OCH2CH3 group in the reaction.
Lab Report 5: Acetylsalicylic Acid (Aspirin) Synthesis Name: Divya Mehta Student #: 139006548 Date Conducted: November 19th 2014 Date Submitted: November 26th 2014 Partner’s Name: Kirsten Matthews Lab Section: Wednesday 2:30 L9 IAs Name: Brittany Doerr Procedure: For the procedure, see lab manual (CH110 Lab Manual, Fall 2014) pages 96-98. Wilfrid Laurier University Chemistry Department. Fall 2014. Acetylsalicylic Acid (Aspirin) Synthesis.
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.
If you’re like me, you love nothing more than getting your feet wet at the ocean. But what if every time you stuck your feet in you were greeted by brackish water? That’s our world if we don’t change. When Oxybenzone, the active ingredient in 70% of suntan lotions, meets coral reefs, only trouble happens.
The yellow solution containing the reactants was slowly poured into the beaker containing the cold water and the acid in order to cause the precipitation of the alcohol, 9-fluorenol and to destroy (hydrolyzed) the unreacted excess sodium borohydride. Subsequently, the white precipitate was vacuum filtered and washed twice with 20.0 ml portions of distilled cold water by pouring the liquid into the Buchner Funnel during filtration. It was necessary to wash the alcohol prior to recrystallization considering that the C-OH bond is easily broken by the formation of a stable and benzylic carbocation that favors the synthesis of difluorenyl ether. Finally, before the purification by recrystallization of the obtained product, the white solid alcohol was allowed to dry over a period of a
Michael Bent Mohamed Mire CHEM 220-12 4/13/2016 Methyl Benzoate Labs The first part of the lab regarded an esterification leading to the formation of Methyl Benzoate (C8H8O2). The purpose of this lab was to convert benzoic acid to methyl benzoate by means of utilizing a reflux acid catalyzed reaction with methanol; purity of the final product was assessed by means of both proton and carbon NMR. The extent to which a reaction’s products are reverted back into the original reactants is denoted by the equilibrium constant. The esterification reaction that's taking place in this lab has a low equilibrium constant (about 2.3) which means that a very low yield of the methyl benzoate product would be generated.
Next, the oxygen is protonated from the 3-nitrobenzaldehyde, which is then followed by an elimination reaction where this acts as a leaving group. The product is the trans-alkene present in the product. After the reaction was completed, purification of the product was conducted using semi-microscale recrystallization.
It is understood the mechanism is acid-catalyzed where protons coordinate with the carbonyl oxygen to make the carbonyl carbon more electropositive for nucleophilic attack (Scheme 1). In the experimental procedure all reactants were added together, this is inefficient as the protons can coordinate with either trans-cinnamic acid or methanol. Coordination with methanol is unnecessary as it reduces its nucleophilicity and makes less protons available to coordinate with the carboxylic acid. To improve
In other lab procedures, benzoic acid is sometimes substituted for anisole in the Friedel-Craft acylation. However, the reason benzoic acid
Quinazolinone is a building block for approximately 120 naturally occurring alkaloids isolated till date from a number of families of the plant kingdom, microorganisms and animals. The first quinazolinone, i.e., 2-cyanoquinazolinone was synthesized in the late1860’s from anthranilic acid and was found to possess anti-convulsant activity. Interest in the medicinal chemistry of quinazolinone derivatives was stimulated in the early 1950’s with the elucidation of quinazolinone alkaloid i.e, 3-[ keto-(3-hydroxy-2-piperdiyl)-propyl]-4-quinazolone from an Asian plant Dichroa febrifugin, which is an ingredient of a traditional Chinese herbal remedy, effective against malaria. Methaqualone was synthesized for the first time in 1951 and it is the most well- known synthetic quinazolinone drug, famous for its sedative and hypnotic