Begin by adding 1 mL of rubbing alcohol to test tube and attach a thermometer to it. b. Place assembly in water bath and begin to heat beaker c. As isopropyl alcohol begins to boil, bubbles begin flowing from the capillary tube d. While temperature is decreasing, record the temp. when the last air bubble comes out of the capillary tube. e. Let assembly cool down and repeat process two more times.
Since (+)-α-Pinene's double bond is trisubstituted and sterically hindered, only two compounds will reaction with borane to form dialkylborane as intermediate. After we get borane in the desired position, we will need to do oxidation process to replace borane by -OH group. Treat dialkylborane with NaOH and H202 to form alcohol and boric acid. Oxygen in hydrogen peroxide will attach to
Discussion and Conclusion In this experiment, the bromination of an alkene will be observed and a mechanism to account for the occurrence distribution of the products will be determined. In the first part of the experiment the 0.9 grams of E-stilbene will be put in a flask with 10ml of dichloromethane and then stirred to affect dissolution of the E-stilbene, since dichloromethane is a nonpolar solvent which can dissolve the nonpolar alkene. After the E-stilbene has been dissolved, 5ml of bromine in dichloromethane will be added, which will be stirred for thirty minutes until the solution is white, to ensure that the reaction has gone to completion. Bromine in dichloromethane is used because dichloromethane works as a good solvent for bromination reactions, due to the fact that it doesn’t react with bromine or most other organic molecules. The reddish color of bromine is discharged upon addition to an alkene as the bromine reacts, making this reaction a useful qualitative test for unsaturation when the reaction has gone to completion.
This technique prevents the product to contact other reactants, and leave the heating environment which might cause side reactions. The removal of the product also helps to shift the equilibrium position of the incomplete reaction to the right hand side, and prevents backwards reaction, resulting in an increased yield of products. This experiment also introduces the idea of azeotrope. An azeotrope is a mixture of two or more pure compounds in such a ratio that its composition cannot be changed by simple distillation. This is because when an azeotrope is boiled, the resulting vapour has the same ratio of constituents as the original mixture of liquids.
The acid used in order to produce acetylsalicylic acid (aspirin) is acetic anhydride and there is no alcohol used so instead another acid called salicylic acid is substituted since it consists of the hydroxyl group. The correct ester name for aspirin is 2-acetyloxybenzoic acid. 5. In order to make the oil of the wintergreen odour, the substances salicylic acid and methanol are required in order to produce the methyl salicylate. However, the difference is the role in which it plays during the reaction since in wintergreen it is substituted as the carboxylic acid but in order to produce aspirin it is used as the alcohol.
Title: Bromination of (E) – Stilbene (Microscale Procedure) Author’s Name: Reinaldo George Professor: Elvis Barrett Date of Experiment: Thursday July 16th 2015 Institution: Nova Southeastern University Abstract The purpose of this experiment was to synthesize the second intermediate in the b series of Sequential Reactions by carrying out the bromination of (E)-stilbene to obtain meso-stilbene dibromide. This product is the precursor to diphenylacetylene, the next synthetic intermediate in the b series. A further purpose of this experiment is to demonstrate the stereospecific addition of bromine to alkenes. The percentage recovery was also calculated and recorded. On completion of this experiment; my lab partners and I were able to successfully synthesize the second intermediate in the b series of the
This explanation can be demonstrated in table 3 also because the results of the reactions demonstrates that chloride reacted more by the color of the product compared to the color of chloride in the mineral oil. Also it also demonstrates that iodine is the weakest oxidizing agent because the results show that iodide didn’t change much from the color that it showed in the mineral oil. In example 6 we have shown the activity series for the halogens used in this
CHEM 2124 Unit 2 Worksheet 2 1) Why does benzene undergo a substitution reaction with Br2 while cyclohexene undergoes an addition reaction? Addition of bromine to benzene is highly unfavorable because it would result in a non-aromatic product. 2) Which is more stable, cyclobutadiene or 1,3-butadiene? Explain 1,3-butadiene is more stable. Cyclobutadiene is antiaromatic and antiaromatic systems are less stable than their open chain counterparts.
CHE 326 Experiment 2 Nitration of Methyl Benzoate I. PRE-LAB (please complete before coming to lab, should be typed, 1 page limit) [pic] A. Table of Reagents (fill in all the blanks as described in the instructions). |Compound |Mol. Weight |mmol |amount |melting point |density |Ref. | | | | |(in g or mL) | | | | |methyl benzoate | | | | | | | |nitric acid | | | | | | | |sulfuric acid | | | | | | | |methanol | | | | | | | |methyl 3-nitrobenzoate | | | | | | | B. References (provide references for the information you've given in the table of reagents) C. Safety (are any of the reagents used toxic or hazardous?