Grignard Reaction Lab Report Assignment

Grignard Reaction Lab Report Assignment Words: 1149

The identity of the product being correct was further confirmed by way of both proton and carbon-13 NORM spectra. This is due to the fact that both spectra yielded peaks that contained the main structural residues, alcohol and aromatic groups, of thermostatically. The final yield of pure thermostatically was 8. 04 grams, resulting in a percentage recovery of 67. 7%. Introduction When faced with the task of needing to form a new carbon-carbon bond in organic chemistry, chemists often turn towards ergonomically reactions.

One particular reaction, the Grinded reaction, allows for a magnesium halide to add o a carbonyl group at the double-bonded oxygen, thus resulting in the converting of the carbonyl containing molecule into an alcohol, as observed in Mechanism 1. However, the carbonyl compound must be chosen carefully, for different carbonyl yield different types of alcohols. Because of the structure of the carbonyl compound, either a primary, secondary, or tertiary alcohol may be synthesized. This is seen in Figure 1.

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But before the actual Grinded reaction occurs, another mechanism must be taken into consideration – the formation of the Grinded reagent. The Grinded agent is synthesized by adding an organic halide, alkyl or aryl, to magnesium in an ethereal solvent. Common halides used are iodides and bromides, although occasionally chlorides may also be used. Fluorides are generally never seen due to their relatively enervative nature. As seen in Mechanism 2, a single electron transfer occurs as both the halide and the magnesium donate an electron to form a magnesium halide. Then, a second single electron transfer occurs through the two radicals.

A reflux apparatus was then set up by first placing a Classes adapter atop the round bottom flask, and adding a condenser, equipped with a thermometer adapter and a drying tube, ND 125 ml separators funnel to the straight arm and curved arms of the adapter, respectively. Via the separators funnel, 40. 0 ml of anhydrous ethyl ether were added to the round bottom flask. After closing the stopcock of the funnel, 5. 3 ml of brokenness and 15. 0 ml of anhydrous ethyl ether were added into the funnel. The two liquids were mixed by shaking and occasional venting of the funnel.

After mixing, half of the brokenness solution was added to the round bottom flask whilst the stirring continued. Then, the rest of the brokenness solution was added at a drop-wise rate. 9. 1 g of phenomenon were next dissolved in 100. Ml of anhydrous ethyl ether in a beaker and transferred into the empty and closed separators funnel. This solution was then added to the round bottom flask at a drop-by-drop rate with stirring. Once funnel was empty, the stir plate was replaced with a steam bath and the flask was heated for approximately 15 minutes.

During the heating, a cold acidic solution was prepared by first filling a 50 ml beaker with ice and carefully adding 4. 5 ml of concentrated sulfuric acid (HOSES) to the ice. This icy acid was then poured into a 250 ml beaker and diluted with tap water until the liquid line reached a volume of 75. Ml. This acid solution was kept on ice until the heating was finished. Once the heating ceased, the drying tube was removed and the cold acid solution was added to the mixture, in a drop-wise fashion via a pipette dropper, through the condenser.

As the acid was being added, the mixture was being stirred over a stir plate. Once completed, the reaction mixture was poured from the round bottom flask into a 500 ml separators funnel and its top (organic) layer was extracted into another beaker. The bottom (aqueous) layer was placed back into the funnel and extracted twice with 50. 0 ml of ethyl ether each. The newly extracted layers were combined and dried over magnesium sulfate (Mages). The dried solution was the decanted into a beaker to remove the Mages salts and the product solution was collected via Boucher vacuum filtration.

The resulting product was transferred into an Erlenmeyer flask with an inverted beaker on top and stored in a drawer. The week after, a rationalizations was performed on the previous week’s crude product. The product ethereal solution was first heated on a steam bath until dry. During the heating, a beaker of methanol was collected and also placed on the steam bath. Once the product was dry, it was lolled to room temperature and then placed in an ice-water bath. The now boiling methanol was added to the crude crystals and a rationalizations was performed.

Once completed, the now purified product was collected via Boucher vacuum filtration and stored in drawer to dry for a week. Afterwards, a melting point range of the purified product was obtained by using a Mel-temp apparatus. Lastly, an infrared spectroscopy spectrum was obtained for the purified solid by using an IR spectrometer. Results Adding the first 40. 0 ml of anhydrous ethyl ether resulted in the solution becoming a brown-orange color. The MGM turnings appeared the same. Gas was formed when brokenness was mixed with the 15. 0 ml of anhydrous ethyl ether.

The solution appeared oily at first, but after shaking, it cleared up. Shaking of the funnel also resulted in more gas bubbles to form. The addition of the first half of the brokenness solution to the reaction mixture resulted in a color change from brown-orange to orange, to bright yellow, to milky yellow, to milky white, then finally to a golden-brown hue. After this color change, the remaining half was added and yielded more color change. From the original golden-brown, the mixture turned a clear fuchsia, then became milky pink. When the mixture of megaphone and 100. Ml anhydrous ethyl ether was added, the reaction mixture became a pale white pink and quickly appeared to solidify. Two layers formed; the top layer appeared milky pink, and the bottom had a cream white hue. Once the addition of the solution was complete, the stir plate was replaced with a steam bath. This heating resulted in the solid-like mixture changing into an orange color. The addition of the cold acid solution resulted in bubbling to occur and the mixture appeared to decrease in amount, as if the acid “burned away”‘ some of the mixture.

Once all of the solid reacted with the acid solution, he mixture yielded two layers. The top layer was clear and yellow while the bottom layer was just clear. During the two extractions with ethyl ether, gas bubbles formed. In both cases, two layers formed yet again. In the first extraction, the top layer had a much fainter yellow color than the original, and the bottom was still clear. By the second extraction, the yellow tint was basically no longer visible. The drying with magnesium sulfate resulted in numerous little Mages salts that had a yellow tint. The remaining product solution appeared clear.

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