In Experiment 13B we generated a Grignard reagent using bromobenzene (the limiting reagent) and magnesium in an ether solvent. This Grignard reagent was then reacted with benzophenone, followed by an acidic workup, to produce triphenylmethanol. The ether solvent was used in this experiment because is helped to stabilize the Grignard reagent by coordinating its lone pair electrons, therefore donating electron density to a electron deficient magnesium molecule. Anhydrous conditions were required because the Grignard reagent is a reactive nucleophile and a strong base. The anhydrous conditions prevent the Grignard reagent from deprotonating water to form benzene. We ensured anhydrous conditions by flame drying all of our glassware.
The reaction began with the insertion of magnesium into the carbon-bromine bond to generate the Grignard reagent. 96 mg of magnesium turnings were ground up with a mortar and pestle in order to remove any surface oxides and contaminations that may preclude magnesium’s ability to react with unreactive alkyl halides. The magnesium turnings, along with a small crystal of iodine and a drop of 1,2-dibromoethane were added to a round bottom flask. The 1,2-dibromoethane is necessary to activate the alkyl halide. In a conical vial 2mL of anhydrous ether
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The remaining organic layer was washed with sodium bisulfite and brine. The sodium bisulfite was used to wash away MgOH and neutralize the acid. The solution was dried using anhydrous sodium sulfate and heated until the solvent evaporated. Anhydrous sodium sulfate is a drying agent used to remove water from the mixture. The crude mixture was triturated in petroleum ether. Trituration broke down the crude mixture into a desirable compound that remained insoluble, and impurities, which were soluble in the liquid. Therefore, the impurities were filtered out using petroleum ether. This rinsed away the non-polar byproduct,
Initially, the entire impure product was mixed with diethyl ether for extraction. Upon mixing, the solution separates into two layers; an organic layer and an aqueous layer. The organic layer contains the desired product. Additional extractions using sodium carbonate solution and sodium hydroxide solution were used as well to ensure removal of undesired molecules. The reason that two layers form is due to the fact that water is immiscible with organic products and diethyl ether meaning that they do not dissolve into one another.
The crude product was washed by taking the reaction product in the separatory funnel and adding 23 mL of deionized H2O. The mixture was shaken and allowed to settle until layers were observable. The top layer was the desired product and approximately 25 mL of aqueous layer was extracted from the separatory funnel. Next, 25 mL of 5% NaHCO3 was added to the separatory funnel in order to neutralize the acid. This mixture was swirled, plugged with the stopper and inverted. Built-up gas was released by turning the stopcock to its opened and closed positions, releasing CO2 by-product. This was done four times in one minute intervals. The solution was allowed to settle until layers were observable. The bottom layer that contained salt, base and water was extracted from the separatory funnel. The crude product was washed again as mentioned previously.
The purpose of this experiment was to synthesize the Grignard reagent, phenyl magnesium bromide, and then use the manufactured Grignard reagent to synthesize the alcohol, triphenylmethanol, by reacting with benzophenone and protonation by H3O+. The triphenylmethanol was purified by recrystallization. The melting point, Infrared Spectroscopy, 13C NMR, and 1H NMR were used to characterize and confirm the recrystallized substance was triphenylmethanol.
The next day an orange goopy textured product resulted. The extracts were then dried and combined with anhydrous sodium sulfate, then evaporated with dry air under the hood in a warm water bath. The liquid was cooled and had an initial weighing of 0.5887g. It was reweighed several minutes later with a final
6. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene; to purify the crude product of either trans-stilbene, cis-stilbene, or styrene reaction.
Wash (swirl and shake) the organic layer with one 10-mL portion of water and again drain the lower aqueous layer. Transfer the organic layer to a small, dry Erlenmeyer flask by pouring it from the top of the separatory funnel. Dry the crude t-pentyl chloride over 1.01 g of anhydrous calcium chloride until it is clear (see Technique 12, Section 12.9). Swirl the alkyl halide with the drying agent to aid the drying.
The Purpose of this experiment is for the students to learn how to use sodium borohydride to reduce benzil to its secondary alcohol product via reduction reaction. This two-step reaction reduces aldehydes by hydrides to primary alcohols, and ketones to secondary alcohols. In order for the reaction to occur and to better control the stereochemistry and yield of the product, the metal hydride nucleophile of the reducing agents such as LiH, LiAlH4, or NaBH4 must be carefully chosen. Being that LiAlH4 and NaBH4 will not react with isolated carbon-carbon double bonds nor the double bonds from aromatic rings; the chosen compound can be reduce selectively when the nucleophile only react with
In a 25-mL round-bottom flask, 1-chlorobutane (5 mL, 4.32 g, 0.046 mol), sulfuryl chloride (1.6 mL, 2.7 g, 0.02 mol), 2,2’-azobis-(2-methylpropionitrile) (0.03 g), and a boiling chip were added. After a condenser and gas trap were attached to the flask, the mixture was heated to a gentle reflux in a steam bath for 20 min. The flask was then allowed to cool down quickly in an ice bath for a short time before a second portion of the 2,2’-azobis-(2-methylpropionitrile) (0.03 g) was added to the flask. The mixture was refluxed for another 10 min. before the flask was cooled in a beaker of water. The reaction mixture was then poured into a small separatory funnel already filled with water (10 mL),
Organometallic compounds are compounds that contain carbon-metal bonds (C-M bonds), in which carbon bears a partial negative charge because metal is less electronegative than the carbon. This partial negative charge of the carbon atom allows it to be a good nucleophile that attacks the electrophile to make a new carbon-carbon bond. There are several examples of organometallic compounds, such as organolithium, Gilman reagents, and Grignard reagents (organomagnesium reagent). In this experiment, Grignard reagents are prepared and reacted with other electrophilic carbon to form a new carbon-carbon bond. Victor Grignard discovered Grignard reagent around 1890s and received a Noble Prize in 1912 with his discoveries. In this experiment, an alkyl halide or aryl halide is reacted with magnesium metal to prepare a Grignard reagent (R-MgX). In this Grignard reagent preparation reaction, halide is typically used with bromine (sometimes with chlorine, not
Through the use of the Grignard reaction, a carbon-carbon bond was formed, thereby resulting in the formation of triphenylmethanol from phenyl magnesium bromide and benzophenone. A recrystallization was performed to purify the Grignard product by dissolving the product in methanol. From here, a melting point range of 147.0 °C to 150.8 °C was obtained. The purified product yielded an IR spectrum with major peaks of 3471.82 cm-1, 3060.90 cm-1, 1597.38 cm-1, and 1489.64 cm-1, which helped to testify whether the identity of the product matched the expected triphenylmethanol. The identity of the product being correct was further confirmed by way of both proton and carbon-13 NMR spectra. This is due to the fact
The purpose of this lab was to synthesize triphenylmethanol from benzophenone and bromobenzene by the formation of a Grignard compound with the reagents bromobenzene and magnesium metal. The bromobenzene was first transformed into the Grignard compound and was then reacted with the benzophenone to make the final product. The mixture was then mixed with sulfuric acid and the organic layer was extracted via a separatory funnel. The mixture was then recrystallized from methanol and was allowed to dry and the percent yield, melting point, and the IR was obtained. The mass of the product obtained was 5.45 grams and the percentage yield was determined to be 41.95%. The melting point range obtained from the final product was 89-91°C
During the halogenation reactions of 1-butanol, 2-butanol, and 2-methyl-2-propanol, there is a formation of water from the OH atom of the alcohol, and the H atom from the HCl solution. The OH bond of the alcohol is then substituted with the Cl atom. Therefore all of the degrees of alcohol undergo halogenation reactions, and form alkyl halides as products. This is because the functional group of alkyl halides is a carbon-halogen bond. A common halogen is chlorine, as used in this experiment.
Objective: The objective of this lab is to observe the synthesis of 1-bromobutane in an SN2 reaction, to see how a primary alky halide reacts with an alcohol.
This was difficult to see the two different layers. The water removes soluble impurities. 7. Collect the organic layer in a 250cm3 beaker and add about 20cm3 sodium carbonate solution. Repeat this step until no more effervescence occurs.
Grignard was the child of a sail producer. In the wake of concentrating on arithmetic at Lyon he exchanged to science and found the manufactured response bearing his name (the Grignard response) in 1900. He turned into an educator at the University of Nancy in 1910 and was granted the Nobel Prize in Chemistry in 1912. Amid World War I, he studied chemical warfare agents, especially the produce of phosgene and the identification of mustard gas. His partner on the German side was another Nobel Prize–winning chemist, Fritz Haber. (2) The Grignard reagent is exceptionally responsive and responds with most natural mixes. It likewise responds with water, carbon dioxide and oxygen. (2) Grignard reagents are set up by the response of magnesium metal with fitting alkyl halide in ether dissolvable. The halogen might be Cl, Br, or I. A standout amongst the most imperative employments of the Grignard Reagent is the response with aldehydes and ketones to frame liquor. A related blend utilizes ethylene oxide to plan alcohols containing two more carbon molecules than that of the alkyl halide. (2)