Benzene and Activating Group

In the mechanism, the olefine in the benzine squall attacks the Br2 sort leaving a carbocation intermediate and a atomic number 35 anion. The Br2 was in an HBr solution, which used as a catalyst kindred to FeBr3. The bromine anion then deprotonated a beta hydrogen, forming HBr and a benzol dance band with the activation substituent and bromine. This chemical answerion could be repeated up to two more generation based on the strength of the orthro/ para directing radical. As a offspring, in that respect were many workable different reapings when the redolent(p) chemical compounds underwent bromination.For aniline, the soothsaying was that the mathematical harvest-home would be 2,4,6-tribromoaniline because gum anime was a genuinely fond activating ag company that reacted coercively with halogenations receptions in general. For phenol, the hydroxy free radical was likewise a wall activating and negatron donating gathering. A disubstituted bromine ingath ering was predicted because the hydroxy conference was non as powerful as the amide. Anisole too had an activating group in a methoxy group and the prediction was from the anisole bromination reception would be a disubstituted convergence.Lastly, for acetamide, the amide group was considered to be not a dependable activating group compared to the anime, hydroxy, and methoxy groups because of the fact that the electrons were not localized in the amide imputable to resonance. As a result, this decreased the activation of the benzene ring and the predicted product was 4-bromo acetanilid. Mechanism (for acetanilide) Results enhance Melting Tempeature (degrees Celsius) ingathering (g) Anisole N/A petroleum aniline 119-120 116-117 0. 116g 0. 010g Phenol N/A 36-51 0. 325 0. 007 phenylacetamide 166-168 156-162 0. 140g 0. 111gCalculations are stick on at the vertebral column Reaction pass Reagant Actual fall in Percent go bad acetanilid acetanilide 0. 140g 65. 4 % parole The reaction that was through with(p) in research laboratory was the bromination of acetamide. Overall, the reaction was picturesque efficient as the percent payoff of the reaction was 65%. Due to development a 10% v/v bromine solution, in that respect was 0. 15 ml (0. 02 seawall) of bromine in 1. 5 ml of the solution. Compared about 0. one hundred thirty-five g of acetamide used (0. 01 breakwater), thither was an excess of bromine to react with the acetamide. As a result, there may view been not becoming acetamide to react with bromine.The product in like manner appeared to be evenhandedly piss soluable, which cut the efficiency. Also, the reactions done by the other groups had similar results or uneffective reactions that had small yields. establish on the run point measurements in lab, the rankings in term of responsiveness were aniline, phenol, anisole, and acetamide. As predicted before, aniline was stratified as the or so labile because the product was 2,4, 6-tribromoaniline, which had a melting point of 119-120 C. The assist most responsive aromatic compound was phenol with products 2,4 and 2,6 dibromophenol at 36 to 51 C.The hydroxy group was a safe(p) activating group, tho not strong enough to actuate the benzene ring for a leash bromination due to the deactivating cause of the added benzylic bromine. The leash most reactive compound was anisole with an oil and possible products for this reaction could be 2 or 4 or 2,6 bromoanisole. found on this reactivity, the methoxy group had steric bulk and the type O in the methoxy favourite(a) to stabilize neighboring bromines. The least reactive compound was acetamide, with a product of 4-bromoacetanilide.The amide group in acetanilide was bulky, so preferring the ortho carriage would mean a more unchangeable product with slight steric interaction. Overall, the predictions in the theory matched besides the anisole. The results curb sense because as the reactivity decreases, it was checkmate to factors such as electron delocalization due to resonance, steric bulk, and bromine beingness a deactivator to the benzene ring. Sources of Errors Sources of errors may result from not crashing the reaction with enough water and sodium bisulfite and not rinsing the product with water during vacuity filtration.Conclusion The product obtained in the reaction was 4-bromoacetanilide and the order of reactivity of bromination was determined. Calculations Mol of bromine 10% v/v = (0. 15 mL Br2) x (3. 11 g/mL) x (159. 81 g/ breakwater) = 0. 003 gram molecule Br2 Mol of acetanilide (0. 135g acetanilide) x (1 mol/135. 17 g) = 0. 001 mol acetanilide Acetanilide is Limiting Reagant. a priori move over (0. 135g acetanilide) x (1 mol acetanilide/135. 17 g) x (1 mol 4-bromoacetanilide/1 acetanilide) x (215. 07 g/1 mol 4-bromoacetanilide) = 0. 215g Percent Yield . 140g/ 0. 215g= 65. 1%