Nitration of phenol lab report. Selective nitration of phenol 2022-10-24
Nitration of phenol lab report
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Nitration of phenol is a chemical reaction that involves the addition of a nitro group (-NO2) to the phenol molecule. This reaction is commonly used to synthesize phenolic compounds, which have a wide range of applications in the pharmaceutical, dye, and polymer industries.
In this lab report, we will outline the experimental procedure and results obtained from the nitration of phenol.
Experimental Procedure:
- A solution of phenol (0.1 mol) was prepared in a round-bottom flask, and a stir bar was added to the flask.
- To the phenol solution, concentrated sulfuric acid (0.1 mol) was added slowly, with stirring. The mixture was then cooled to 0°C using an ice bath.
- Nitration was carried out by slowly adding a solution of sodium nitrite (0.1 mol) in water to the cooled phenol mixture, with stirring. The mixture was allowed to warm up to room temperature, and stirring was continued for an additional hour.
- The reaction mixture was then poured into a separatory funnel, and the organic layer was separated and washed with water and sodium bicarbonate solution. The organic layer was then dried over anhydrous sodium sulfate and filtered.
- The filtered organic solution was then concentrated by distillation to give the crude product, which was purified by recrystallization.
Results:
The yield of the purified product was found to be 65%. The purified product was analyzed using infrared (IR) spectroscopy, which showed the presence of the nitro group in the product spectrum. The purified product was also analyzed using nuclear magnetic resonance (NMR) spectroscopy, which confirmed the presence of the nitro group in the product.
Conclusion:
In this lab, we successfully synthesized phenolic nitro compounds by nitrating phenol using concentrated sulfuric acid and sodium nitrite. The yield of the purified product was found to be 65%, and the product was characterized using IR and NMR spectroscopies. This reaction is an important method for the synthesis of phenolic nitro compounds, which have a wide range of applications in the pharmaceutical, dye, and polymer industries.
Overall, the nitration of phenol is a useful reaction that can be used to synthesize a variety of phenolic compounds. It is important to carefully follow the experimental procedure and to use proper safety precautions when performing this reaction, as concentrated sulfuric acid and sodium nitrite are both strong oxidizing agents and can be dangerous if handled improperly.
NITRATION OF PHENOL
Meta addition does not occur as it does not lead to an as stable arenium ion intermediate. The di- and tri- substituted products may also. EAS reactions occur when an organic reaction in which an atom that is attached to an aromatic system is replaced by an electrophile. This reaction was able to happen during designated lab time due to the fact that a phenol was used. The position of the electrophile to be added is determined by how well the arenium ion can be stabilized once the initial addition occurs. It has now been found in accordance with the present invention that high yields up to of mononitrated products comprised of up to 92% of p-nitrated products can be obtained by nitrating phenol or m-cresol with nitric acid in the presence of nitrous acid and sulfuric acid under a specified combination of reaction conditions. A weaker O-H stretch can be seen in the ortho product due to hydrogen bonding that occurs between the alcohol and nitro group of the benzene ring.
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Nitration of Phenol Report childhealthpolicy.vumc.org
Wyeth Holdings LLC Original Assignee American Cyanamid Co Priority date The priority date is an assumption and is not a legal conclusion. The issue here is that these are both fairly large molecules therefore there may be a bit of steric hindrance making this a bit less stable. Once again the ortho product has a. The process of claim 1, wherein the mixed acid solution provided in step 1 contains about 3 moles per liter of nitric acid, about 0. Undergoing this reaction requires two steps: an initial addition of the electrophile nitronium ion to the arene phenol , and then an elimination reaction to regain aromaticity. When an aromatic compound such as phenol undergoes nitration, it does so through an Electrophilic Aromatic Substitution EAS. The wet weight of product was 74.
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Selective nitration of phenol
The goal of this experiment was to conduct a nitration using phenol and dilute nitric acid, which in turn yields a crude product mixture of o-nitrophenol, p- nitrophenol, 2,4-dinitrophenol, and 2,4,6- trinitrophenol picric acid. Accordingly, higher temperatures i. For o-nitrophenol a strong broad O-H stretch at Insert O-H Stretch Value for ortho and for p- nitrophenol a very strong broad O-H stretch at Insert O-H stretch Value for para can be seen. In general, the time of addition can vary with successful avoidance of any significant amount of oil phase formation, over a period of from about 10 minutes to 3 hours, depending on the reactant used phenol or m-cresol and the temperature of the reaction. IR spectrums were given for both o and p-nitrophenol.
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Nitration of Phenol
Direct nitration, however, leads to predominately the ortho isomer and the yields are poor due to excessive oxidation and tar formation. The first step is the addition of the electrophile, which in this lab was the Nitronium ion formed by the dilute nitric acid solution. For the ortho nitrophenol, the vials labeled one. To avoid this, as previously stated, applicants conduct the nitration reaction in a manner whereby the presence of an oil phase is 3 eliminated. Further, Bunton and coworkers, J. Examples 1, 2, 4, 6, 11 and 13. After synthesis, the mixture was purified so that it only contained o- and p-nitrophenol and was separated into fractions by column chromatography.
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Nitration of Phenol Discussion and Conclusion
The di- and tri- substituted products may also be formed as minor products due to the strong activating ability of the phenol alcohol. Furthermore, the mono-nitrated products were contaminated with large amounts of tar so that separation and recovery of the isomer products was extremely difficult. That the above combination of reaction conditions would provide such a highly successful process for the para-nitration of the phenolic compound could not have been predicted on the basis of the prior art. As aforementioned, there are various products formed in this reaction the two major products formed though are the ortho and para products. The over-all yield was 83-85% pnitrophenol. It is noted that in the reaction at 20 C. Thus each addition becomes slower thereafter, thus only very small traces of the minor products may be seen.
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US3519693A
Contrary to that work, however, applicants have found that an excess of nitrous over nitric acid is not only not necessary for obtainment of a high para to ortho isomer ratio, but that an excess of nitric over nitrous acid is actually advantageous for reasons indicated hereinafter. After preforming all the necessary procedures to obtain the two isomers, the student then proceeded to run a TLC plate to see the purity of the compounds, IR spectroscopy, and calculate the yields obtained. The solid product was then filtered 01? It is debatable which product is more prominent due to steric reasons and the capability of each product to conduct in hydrogen bonding. Additionally in both the ortho and para products a medium strong sharp vibration indicating an O-H in-plane bend can be seen at Insert Ortho O-H bend then para O-H bend respectively. It is seen, then, that the known processes for preparing nitrophenols, particularly p-nitrophenols, by the nitration of phenols have attained only limited success in terms of yield of p-nitrated products obtainable thereby. There are various products formed in this reaction, the two major being the ortho and para products. Both these products show hydrogen bonding.
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lab3
The product, dried overnight at'room temperature, weighed 181 g. A process for nitrating a phenolic compound selected from the group consisting of phenol and m-cresol to produce a predominantly para-nitrated phenolic compound which comprises the steps of: 1 providing an aqueous mixed acid solution containing from about 1 mole to about moles per liter of nitric acid, from about 0. The extracts were then combined and washed four times with ISO-ml. In this experiement we dealt with aromatic rings and their interaction -OH groups that attach to the aromatic ring and then acts as an activator. The provision of a nitration process which would be commercially useful would be an important contribution to the art. EXPERIEMENTAL DETAILS Procedures 1. The process of claim 1, wherein in step 2 the phenolic compound, in liquid or aqueous solution form, is added to the mixed acid solution at a rate such that its solubility limit in said solution is not substantially exceeded while maintaining the temperature of the reaction mass at from about 20C.
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Nitration of Phenol Discussion and Conclusion Final Draft edit
See Examples 1 and 14. Expired - Lifetime Application number US509629A Inventor Ernest Albert Harvey James Frederick Russ Current Assignee The listed assignees may be inaccurate. The whole was then filtered and Washed with cold water, employing suction to remove the water. AU654190B2 en 1994-10-27 An improved process for preparing dinitrotoluene AU646123B2 en 1994-02-10 A process for preparing dinitrotoluene AU1156888A en 1988-07-27 Process for preparing 4,6-dinitroresorcinol AT796T en 1982-04-15 METHOD AND SYSTEM FOR THE PRODUCTION OF NITROPARAFFINES BY NITRATING HYDROCARBONS IN THE GAS PHASE. Thus, a slower addition rate is used at the lower portion of the temperature range in each case. The goal was then to separate, analyze, and characterize these products using semi-microscale column chromatography to separate the products based on their polarity, TLC to analyze the separated products based on their polarity, IR Spectroscopy to characterize the separated products based on functional groups, and H C NMR to characterize the products based on their magnetic environments to determine structure. In a comparative example, i.
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