Pyridinium Hydrobromide

Discussion: In the synthesis of 1-bromobutane alcohol is a poor leaving group; this problem is fixed by converting the OH group into H2O, which is a better leaving group. Depending on the structure of the alcohol it may undergo SN1 or SN2. Primary alky halides undergo SN2 reactions. 1- bromobutane is a primary alkyl halide, and may be synthesized by the acid-mediated reaction of a 1-butonaol with a bromide ion as a nucleophile. The proposed mechanism involves the initial formation of HBr in situ, the protonation of the alcohol by HBr, and the nucleophilic displacement by Br- to give the 1-bromobutane. In the reaction once the salts are dissolved and the mixture is gently heated with a reflux a noticeable reaction occurs with the development of two layers. When the distillation was clear the head temperature was around 115oC because the increased boiling point is caused by co-distillation of sulfuric acid and hydrobromic acid with water. When transferring allof the crude 1-bromobutane without the drying agent,

A 0.5 g of sodium tungstate dihydrate was weighed and transferred into a 50-mL round-bottom flask with a magnetic stir bar. Approximately 0.6mL of Aliquat 336 was then transferred carefully into the round bottom flask using a 1mL syringe. The round bottom flask and its contents were then set up in an oil bath. 11mL of 30% hydrogen peroxide and 0.37 g of potassium bisulphate were added to the reaction mixture in the round bottom flask and stirred using a magnetic stirrer. Lastly, 2.5mL of cyclohexene was added using automatic dispenser and the mixture stirred. A condenser was fitted on the round bottom flask, clamped and attached to water horses. The reaction mixture was then heated on the oil bath and the reflux process initiated for an hour while stirring the mixture vigorously. Half way while rinsing, any trapped cyclohexene in the condenser was rinsed. After 1 hour, the round bottom flask was rinsed

Experimental Method: A filtration apparatus was set up. Solid iron(III) chloride hexahydrate was dissolved in water. In a separate container, sodium acetate trihydrate (NaC2H3O2 x 3 H2O) was also dissolved in water. Sodium acetate trihydrate was then added to iron(III) chloride. 2, 4-pentanedione (C5H8O2) was dissolved in methanol; it was then added to the iron(III) chloride/sodium acetate solution. The product of this mixture was filtered, and the precipitate

In this experiment, an unknown Grignard reagent was prepared from an aryl halide. The unknown reagent was then reacted with carbon dioxide to form a carboxylic acid. The solid acid was then isolated and recrystallized before the melting point was taken. The precipitate was then dissolved in water and titrated to determine the molecular weight. The melting point and molecular weight were then used to determine the unknown acid obtained from the experiment.

The objective of this laboratory experiment is to study both SN1 and SN2 reactions. The first part of the lab focuses on synthesizing 1-bromobutane from 1-butanol by using an SN2 mechanism. The obtained product will then be analyzed using infrared spectroscopy and refractive index. The second part of the lab concentrates on how different factors influence the rate of SN1 reactions. The factors that will be examined are the leaving group, Br – versus Cl-; the structure of the alkyl group, 3◦ versus 2◦; and the polarity of the solvent, 40 percent 2-propanol versus 60 percent 2-propanol.

8. ISBN: 0-558-05245-2 Virtual ChemLab: General Chemistry, Student Lab Manual/Workbook, V. 2.5, Third Edition, by Brian F. Woodfield and

The objective of this lab was to determine the melting point of the diphenylacetylene, which then shows the purity of the compound. E-stilbene was put through an addition reaction with pyridinium perbromide and CH3CO2H to form an intermediate. This intermediate was then the starting material for the elimination reaction with KOH and triethylene glycol to produce diphenylacetylene. Both reactions required the use of suction to dry the crystals. Pure diphenylacetylene has a melting point of 61 degrees Celsius and the intermediate has a melting point of 236-237 degrees Celsius; the closer the temperature is to 61, the purer the final product.

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.

The purpose of this experiment is to examine the reactivities of various alkyl halides under both SN2 and SN1 reaction conditions. The alkyl halides will be examined based on the substrate types and solvent the reaction takes place in.

The first purpose of the lab was to prepare an unknown organomagnesium bromide, an organometallic reagent, reacting an unknown aryl bromide with magnesium in anhydrous ether. The unknown was chosen from a predetermined list of benzoic acid derivatives with varying molecular weights and melting points (see Supplement C). The second purpose of this lab was to prepare an unknown carboxylic acid by reacting the unknown aryl-magnesium bromide with carbon dioxide and diethyl ether then protonating.The third purpose of this lab was to determine the neutralization equivalence point of the unknown carboxylic acid by titrating with sodium hydroxide. The fourth purpose of this lab was to ascertain the identity of the unknown carboxylic acid, and thus the original unknown aryl bromide, using its molecular weight determined from neutralization and melting point.

Figure 2.6 shows the structure of N-methyl-2-pyrrolidone (NMP) used. A polymer must be dissolved in solvent to mix well for membrane fabrication. N-methyl-2-pyrrolidone was used as a solvent in this study. According to Hilal, Ismail & Wright (2015), the membrane porosity and water permeability of the membranes were dependent on the diffusivity of solvent and non-solvent used.

An ester was synthesized during an organic reaction and identified by IR spectroscopy and boiling point. Acetic acid was added to 4-methyl-2-pentanol, which was catalyzed by sulfuric acid. This produced the desired ester and water. After the ester was isolated a percent yield of 55.1% was calculated from the 0.872 g of ester recovered. This quantitative error was most likely due to product getting stuck in the apparatus. The boiling point of the ester was 143° C, only one degree off from the theoretical boiling point of the ester 1,3-dimethylbutyl, 144 ° C. The values of the

Phenazopyridine known as pyridium is a commonly prescribed urinary tract analgesic. Ingestion of large quantities of pyridium can induce significant methemoglobinemia and other complications such as yellow discoloration of skin, hemolytic anemia, hepatitis and acute renal failure. We report a case of 39-year-old female with history of recurrent urinary tract infections complicated by nephrolithiasis presents with shortness of breath, yellow discoloration of sclera and urine after ingestion of 10tablets of 200mg pyridium over a period of 10days. Early recognition of methemoglobinemia and appropriate management is crucial.

An alcohol is being turned into an ester; where, the hydrogen of the hydroxyl group is removed by a carbonate anion and the remaining phenoxide anion backside attacks an ethyl iodine to obtain an ethyl group. If the reaction is successful the melting point should be around 134˙C and the IR spectrum should not have a peak around 3400 cm-1 (hydroxyl bond). To begin the experiment methyl ethyl ketone (solvent) is added to a vial containing the reagents of the reaction: acetaminophen, ethyl iodine, and potassium carbonate. This vial was

Subsequently, 10mL of 3.5% H2O2 were added dropwise to the reaction mixture and was stirred for 20 minutes before heating to boiling at 80°C for 5 minutes. The reaction mixture was then taken off heat and allowed to cool undisturbed in an ice-bath for 30 minutes. Suction filtration was performed after to collect the crystals from the chilled solution The product was then washed with chilled 95% ethanol (2 x 15mL) and followed by diethyl ether (2 x 10mL). The crude product was then left to dry before recording the yield. 20mg of the crude product is then accurately weighed out and dissolved in deionized water in a 25mL volumetric flask. Deionized water was added to the volumetric flask to the mark and the UV-vis absorption spectrum of the crude product was recorded.