Preparation of 4-Bromoaniline

Better Essays
Preparation of 4-bromoaniline
Introduction
Aromatic compounds tend to undergo electrophilic aromatic substitutions rather than addition reactions. Substitution of a new group for a hydrogen atom takes place via a resonance-stabilized carbocation. As the benzene ring is quite electron-rich, it almost always behaves as a nucleophile in a reaction which means the substitution on benzene occurs by the addition of an electrophile. Substituted benzenes tend to react at predictable positions. Alkyl groups and other electron-donating substituents enhance substitution and direct it toward the ortho and para positions. Electron-withdrawing substituents slow the substitution and direct it toward the meta positions.
Aromatic compounds also undergo reactions in their side-chains, often at the benzylic position next to the aromatic ring. Reactions at benzylic positions are often promoted by resonance stabilization of the intermediate and/or transition state with the aromatic ring.
Aromatic amides are formed via electrophilic substitution. The NH2 group is electron-donating and therefore the substituted ring is considered “activated” and will often react even without a catalyst. The nitrogen based activating group increases reactivity by a resonance effect: The resonance stabilisation from an amide group in an aromatic compound is mainly due to the delocalisation of the nitrogen lone pair onto the amide oxygen (which makes the lone pair less available to the aromatic ring) and the increased steric bulk of the group, favouring substitution at the 4-position over the 2-positions which it shields.
Aniline is the simplest aromatic amine and is synthesised by first nitrating benzene using a concentrated mixture of nitric acid and sulphuric acid to give nitrobenzene which is then hydrogenated in the presence of a nickel catalyst to give the final product. Aniline undergoes very readily electrophilic substitution reactions as the aromatic ring of aniline is very electron



References: 1. Harwood, L.M.; Moody, C.J.; Percy, J.M.; “Experimental organic chemistry: standard and microscale”, Blackwell Science 1999, Edition 2; p439-443. 2. http://www.chemicalbook.com/ChemicalProductProperty_EN_CB9760655.htm 3. http://www.chemexper.com/chemicals/supplier/cas/103-88-8.html 4. http://www.uni-r.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/chembox_brom_arom-e.htm 5. http://edivini.pbworks.com/f/bromination_acetanilide_JCE1996p0267.pdf

You May Also Find These Documents Helpful

  • Satisfactory Essays

    EXP-10 CHEM 233L SYNTHESIS OF p-BROMOANILINE Introduction: In this experiment, p-bromoaniline was synthesized in three steps starting from aniline. Since the amino group of aniline is a strong activator of aromatic ring, direct bromination is impractical (equation 1). In order to make a desired product, amino group needed to be protected as the acetamide which also maintained ortho and para position but slowed down the rate of reaction (equation 2). Slow reaction rate would increase…

    • 1494 Words
    • 6 Pages
    Satisfactory Essays
  • Powerful Essays

    Preparation

    • 15550 Words
    • 63 Pages

    OECD DEVELOPMENT CENTRE Working Paper No. 129 (Formerly Technical Paper No. 129) ECONOMIC REFORM IN EGYPT IN A CHANGING GLOBAL ECONOMY by Joseph Licari Research programme on: Strengthening Links between Developing Countries: Regional Co-operation and Integration December 1997 OCDE/GD(97)226 TABLE OF CONTENTS ACKNOWLEDGEMENTS ........................................................................ 6 RÉSUMÉ .....................................................................................…

    • 15550 Words
    • 63 Pages
    Powerful Essays
  • Satisfactory Essays

    Preparation Questions

    • 817 Words
    • 4 Pages

    Indian Market Session 4: Preparation Questions 1. Evaluate L'Oreal's entry strategy in the Indian market with respect to the product, promotion, pricing and place decisions? 2. What have been the changes in the marketing strategy of L'Oreal in the last 8 years? Evaluate them with respect to selection of product / market and each element of the marketing mix? 3. What factors helped the rapid adoption of Excellence colorants among its target customers? 4. Evaluate the options available…

    • 817 Words
    • 4 Pages
    Satisfactory Essays
  • Good Essays

    Solution Preparation

    • 418 Words
    • 2 Pages

    Experiment 5 Solution Preparation 1. Why should the solutions be prepared with 0.10M HCl used as solvent? a. What will happen to Fe3+ if the solution was not prepared using 0.10M HCl? b. Give the balanced equation for the 1st hydrolysis of Fe3+. c. What is the color of the product of 1st hydrolysis of Fe3+? d. What is the effect of the product of 1st hydrolysis to the absorbance of the solution? Determination of Analytical Wavelength 2. Why should the…

    • 418 Words
    • 2 Pages
    Good Essays
  • Better Essays

    Preparation Of Triphenylmethanol Objectives 1. To study the preparation of triphenylmethanol using through Gridnard reaction 2. To study the operations of anhydrous reaction, water vapor distillation. Principles Alcohol is widely used in organic chemistry, not only as solute but also as intermediate to synthesize halide, alkene, ether, aldehyde and ketone etc. In laboratory, an important method of synthesizing alcohol is though the addition reaction of Gridnard reagent and carbonyl compound, whereas…

    • 1134 Words
    • 4 Pages
    Better Essays
  • Satisfactory Essays

    Buffer Preparation

    • 1247 Words
    • 5 Pages

    Buffer Preparation (Gozani Lab) 1. 1 M Tris-HCl Buffers pH Volume (L) TrisBase (g) HCl (ml) pH 7.0 2 242.2 150-155 pH 7.5 2 242.2 120-125 pH 8.0 2 242.2 80-85 Autoclavable. 2. EDTA 0.5 M (pH8.0) 0.5M, 1L: 148 g EDTA + ~30-40 g NaOH to adjust pH (or 186 g EDTA-Na.2H2O + ~20 g NaOH) Note: pH adjusted by NaOH is essential for solubility. Autoclavable. 3. TAE DNA Electrophoresis Buffer (50 X) (2 M Tris, 50 mM EDTA) 2L 484 g Tris 114.2 ml glacial acetic acid 200 ml 0.5 M EDTA 8.0 To make…

    • 1247 Words
    • 5 Pages
    Satisfactory Essays
  • Good Essays

    Educational Preparation

    • 988 Words
    • 4 Pages

    Educational Preparation Lara M. Abdallah Grand Canyon University: Professional Dynamics May 17, 2011 The different options to obtain a nursing degree, while having the same outcome, are not always the best option. While the Associate (AND) Degree nurse is able to take and pass the NCLEX exam there are stark differences with the Bachelor (BSN) Degree nurse. Length of time, cost, experience, and educational training. While the BSN nurse was trained two years in the classroom and three years in…

    • 988 Words
    • 4 Pages
    Good Essays
  • Better Essays

    Educational Preparation

    • 997 Words
    • 4 Pages

    Educational Preparation juli mar Grand Canyon University NRS 430 12-18-11 Educational Preparation There are 2 common, but different, pathways to receiving a RN license. You can earn a bachelor’s degree (BSN) or an associate degree, (ADN). While there are similarities between the two programs, a BSN takes two additional years of college at a university. Both programs teach nursing skills, electives ,science courses, and clinicals. But, the BSN program is a more in-depth study of nursing…

    • 997 Words
    • 4 Pages
    Better Essays
  • Satisfactory Essays

    Preparation of an Ester

    • 598 Words
    • 3 Pages

    concentrated sulfuric acid were placed in a 50 ml flask. 2. Added afew boiling chips and assembled the refluxing apparatus as shown in the diagram below 3. Connected the tubing to the tap and condenser and turned on the water to a uniform flow 4. Heated the mixture on a heating mantel for approx. 30 mins and allowed to cool for 5 mins. 5. Carefully removed the flask and poured the content into a separating funnel containing 10-15 ml water.Shaked flask and allowed the layers to separate,drained…

    • 598 Words
    • 3 Pages
    Satisfactory Essays
  • Good Essays

    Educational Preparation

    • 984 Words
    • 4 Pages

    Educational Preparation – The Differences in Competencies of Registered Nurses with and Without Baccalaureate Degrees Educational Preparation – The Differences in Competencies of Registered Nurses with and Without Baccalaureate Degrees Nursing is a profession with great honor and satisfaction. Patients trust nurses in the most difficult times of their lives. Nursing avails itself many opportunities to grow and practice at several different levels. Not only is there the Licensed Practical Nurse…

    • 984 Words
    • 4 Pages
    Good Essays