Question

Bromination of trans-Stilbene Introduction can drastically valla very viss The alkene halogenation reaction is a class of reacties in which ha s as clectrophiles 10 attack double bond. Reactivity of halogens can drastically in the fileness of a halogenation react For example, the high reactivity of fluorine e of jodine results in very slow orine pas causes a very vigorous reaction while the low reactivity reactions. Chlorine and bromine showmoderate reactivity and a commonly used in this type of reaction: however their r e mature and difficulty in handling limits their use in laboratory settings. Therefore many rements are developed as an alternative to the conventional procedures. Polymer supported reapeals for emple have become a subject of interest The attachment of a reagent (in this case bromine) to an insoluble macromolecular polymer can solve the problems of difficulty in handling conventional and work un procedure, and toxicity. Additionally, since the polymer is insoluble, it can be easily recycled to prepare more bromana n d hominating reagent to carry o reagents. In this experiment, you will be using a polymer u bromination of trans-stilbene reaction. Polymer Supported Brominating Agent Objective • Perform a bromination reaction • Monitoring the completion of the reaction using TLC • Work-up and characterize the final product Safety Precautions!! Wear PPE at all times. Chloroform is hazardous in case of skin contact, eye contact, ingestion, and inhalation. Keep the reaction mixture and the solvent in a fume hood at all times. Check glassware for cracks and chips. Heating chipped or cracked glassware is a safety hazard.. Procedure WASTE REMINDER: Dispose of all waste in the designated waste container. mg of polymer supported brominating agent. Add 2 mL chloroform. Assemble the air condenser and place the set up on an aluminum block. Make sure to secure your setup using proper clamps. Turn on stirring and adjust the heating to 55 °C. SETTING UP THE EXPERIMENT: To a 5 ml glass conical vial equipped with Starring bar, add 18 mg of trans-Stilbene and 103

Answer 1

• This question is based on the synthesis of organic compound.
• In every organic compound synthesis, some basic things be remember.
• In order to perform any synthesis reaction, First of all it is necessary to selection of appropriate reagents.
• Thin-layer chromatography (TLC) is a very important technique to monitor the reaction or to predict the reaction completion.
• Thin-layer chromatography technique is used for the separation of various non-volatile mixtures.
• Thin-layer chromatography is performed on a sheet of glass or aluminium foil and it is coated with a thin layer of adsorbent material such as silica gel, aluminium oxide (which is also known as alumina) or cellulose.
• TLC is help in monitoring the reaction by spotting the starting material and reaction mixture after did the reaction and it is giving the Rf value of both starting material as well as reaction mixture which is forming product.
• TLC tells us about the reaction being completed and the somehow the yield of the product formation. In this way, TLC helps us in organic synthesis.
• After TLC, The work up of reaction is performed and the yield of product is measured.
• After that, final characterization is done by NMR Spectroscopy which tells us about the skeleton of structure of product formed.
• The bromination is done easily rather than the flourination and iodination.
• The colour is a useful indicator of this reaction because the colour of bromine will be little reddish brown and it will help in predicting the reaction completion.
• We can improve this experiment by using other bromine compounds which are commercially available.
• For the percentage yield, the measured yield and the theoretical yield is important. By comparing the experimental yield with the theoretical yield from the literature we can calculate the percentage yield.