Bromination of Acetanilide

BROMINATION OF ACETANILIDE accusativeAim of the experiment was too bromate acetaldehyde to pattern p-bromo acetanilide.INTRODUCTIONphenylacetamide is a chemic compound with the chemical formula of C6H5NH(COCH3). It is a crystalline material that is prepa reddened by acetylation of analine and is widely utilize in the color industry. This crystalline fast is an odourless unhurt chemical that has a flake or leaf handle appearance. It is in any case known as N phenylacetamide, acetanil or acetanilide. Its former trade mark was antifebrin. As mentioned earlier acetanilide apprize be produced by reacting acetic anhydride with aminobenzine.C6H5NH2 + (CH3CO)2O C6H5NHCOCH3 + CH3COOH (http//www. mendelset. com/articles/680/prepa ration-recrystallization-acetanilide) (regensburg. de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/Grafik/box_brom_ar1. gif) The endorsement figure illustrates the process utilize in the laboratory to form bromoacetanilide. Recrystallizatio n is of secern splendor in the experiment because this method is utilize to obtain the crystals. Recrystallization is a purification proficiency that removes impurities from a sample. An impure solid is fit(p) in a liquid for sample wet or ethanol. It is and hence alter making the solid dissolve into the resolutenessant.When the solvent cools back down again, the solid go turn out precipitate out of the solution and present the impurities behind, still dissolved in the solvent. This method purifies the solid. acetanilide has many uses in some(prenominal) pharmaceutical and manufacturing industry. It is use as a precursor in the synthesis of penicillin and early(a) pharmaceuticals. Originally it was the first aniline observed to posses analgesic and antipyretic properties. A. Cahn and P. Hepp introduced it in the health check correction in 1886. It was later to be discontinued in the medical field because of its toxic nature that was believed to cause cyanosis i n the patient.Through further research it was also find that acetanilide is metabolized in the body to form paracetamol which was responsible for the analgesic and antipyretic property. Acetanilide is also used as an inhibitor in hydrogen peroxide and is used to stabilize cellulose ester varnishes. It is also used in mediation in rubber accelerator synthesis, dyes and dye intermediate synthesis and camphor synthesis. It is also used in the manufacture of sulfa drugs as it used for the production of 4-acetamidobenzenesulfonyl chloride, which is a key intermediate during this manufacture. METHOD 4. g of acetanilide was placed in a 100cm3 cone-shaped flask. It was whence dissolved by adding 20 cm3 of glacial acetic acid, which was measured out in a measuring cylinder. 7. 0 cm3 was dispensed directly into the conical flask by use of a buret in one portion. The flask was then swirled to mix the contents. It was then covered with a clock glass and left in the fume hood for precisely 30 minutes long and swirled occasionally during the duration. aqueous sodium hydrogen sulphite solution was added into the beaker until the red colour of the reactant disappeared this was to chequer that surplusage atomic number 35 formed during the chemical answer was destroyed.Feature name Free-Radical BrominationThe lumps of solid found in the scum bag of the flask were broken up to picture no trapped atomic number 35 remained. As a precaution the first social function of the experiment, which is outlined above, was carried out in a fumed cupboard. The flask was then interpreted out of the cupboard and the solid was then filtered by sucking filtration use a Buchner funnel and washed with distilled water (2x 25cm3 portions). As much water as thinkable was removed from the solid by sucking filtration then transferred to a 100cm3 conical flask.The rasping solid was recrystallized by use of a minimum volume of a variety of ethanol and water in the ratio 2 1 at its boil ing point. This mixture was added in portions using a steam bath as a heat source. The clear solution was then set aside to cool to secure room temperature. The flask was cooled thoroughly in an ice/water bath afterward the crystals were collected by suction filtration using a Hirsch funnel. The crystals were then washed with round 1cm3 of ice-cold ethanol/water mixture, change by suction filtration and the mass and thawing point range recorded.RESULTS Mass of vacant weighing boat 2. 25g Mass of go off weighing boat+crystals 5. 09g Mass of crystals 2. 8g resolve range 162 170C DISCUSSION Bromine is for the most part a toxic, corrosive and a strict irritant to lung and eye tissues. Necessary precautions were taken during the experiment. One of the precautions taken was handling of the atomic number 35 solution in the reaction was through in a fumed cupboard. The excess bromine that was in the reaction was alone destroyed by adding aqueous sodium hydrogen sulphite solut ion.Protective gloves were worn to prevent the bromine liquid, ethanoic acid and sodium hydrogen sulphite from afflictive the scrape up, as they are all skin irritants. The reaction that was carried out in the first part of the experiment is an electrophilic aromatic substitution. In the electrophilic aromatic substitution, an electrophile reacts with the benzene ring this result in an electrophile replacing hydrogen in one of the phenyl carbons such that the product of the reaction has the electrophile bonded to one of the phenyl carbon.We did not use aniline in this serviceable as it has carcinogenic properties instead we used acetic anyhidride which is a milder version. The other products formed in this reaction hydrogen bromide and can be collected by hydrolizing(removing the hydrogen) to obtain the bromine. The part yield of the rection was calculated as follows Maas of products was 2. 84g milling machinery mass of bromo acetanilide=214 0. 284/ 214 = 0. 00133 4. 5g of acet anilide used Molar mass = 135 0. 45/134 = 0. 003 Yield 0. 00133/0. 003x 100 = 44. 3% yield.As understandably illustrated the percentage yield is less than a 100% this could be due to a number of reasons like some of the solid might have been lost during the suction or while washing the crystals with the water and ethanol mixture the weighing scales could also have been inaccurate. CONCLUSION Better practical methods are required during the experiment to ensure a 100% yield. REFERENCES http//www. mendelset. com/articles/680/preparation-recrystallization-acetanilide regensburg. de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/Grafik/box_brom_ar1. gif)