Experiment 3 Lab Report PDF

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Julianna Norrell 3.6.21, CHEM 3106-301 TA: Hao Liu Part II of Hydroboration-Oxidation of an Alkene to Yield 1-Octanol Purpose: The purpose of this experiment was to produce a hydroboration-oxidation reaction of an alkene in order to produce 1-octanol Reaction and Physical Properties Table: Compounds, Solvents, and Reagents 1-octene BH3-THF (1M) NaOH (aq) (3M) H2O2 Diethyl ether 1-octanol

MW (g/mol)

Amount (mL)

mmol

Bp (oC)

Density (g/ml)

112.22 82.92

0.400ml 2.0ml

2.57 21.7

121.01

0.72 0.898

-

0.6ml

-

-

-

72.12 130.30

0.6ml -

-

34.6 194.8

0.71 0.83

Safety: All Safety data obtain from Thermofisher SDS 1-Octene (Flammable) Risk Statements: flammable liquid and vapor, causes irritation Safety Statements: wear all proper protective clothing, keep away from open flames BH3-THF (Flammable) Risk Statements: flammable liquid and vapor, causes irritation Safety Statements: wear all proper protective clothing, keep away from open flames NaOH (Corrosive) Risk Statements: corrosive to skin and eyes, causes burns and eye damage Safety Statements: wear all proper protective clothing, wash any exposed skin H2O2 (Irritant) Risk Statements: corrosive to skin and eyes, causes burns and eye damage Safety Statements: wear all proper protective clothing, wash any exposed skin\ Diethyl Ether (Flammable) Risk Statements: flammable liquid and vapor, causes irritation Safety Statements: wear all proper protective clothing, keep away from open flames 1-Octanol (Irritant) Risk Statements: corrosive to skin and eyes, causes burns and eye damage Safety Statements: wear all proper protective clothing, wash any exposed skin\

Procedures: 1. Add 0.6ml of 3M NaOH to conical vial, make sure spin vain is present and long point of triangle down. 2. Fit vial with water condenser and run water through the condenser 3. Use 1 ml disposable syringe to slowly add the 0.6ml of H2O2 through condenser with 510 minutes with stirring 4. Warm mixture to 45oC either using a water bath or heating on a hot plate. (If hot plate set to roughly 60oC) 5. Reaction should be checked with an infrared thermometer. Allow heating for 1 hour, cool, and then proceed to next step. 6. Add roughly 1 ml diethyl ether to the concial vial then mix, then use pipet to transfer mixture to separatory funnel to facilitate extraction. Rinse vial with 2 ml more of diethyl ether and combine with mixture in separatory funnel. 7. If there is a solid, add 1 ml HCl to funnel and mix. 8. Remove aqueous layer from funnel 9. Extract organic layer with 2 ml HCl solution. Mix and vent and then remove the aqeous layer. 10. Extract organic with 1 ml of water. Check pH is close to 7. If not close then extract with another 1 ml of water. 11. Transfer to small beaker or flask for drying. Dry by adding small amounts of MgSO4 to the mixture. 12. Transfer to pre-weighed vial and then filter. (can be done with heat and air in the hood) 13. Record observations and describe crude product 14. Obtain a GC and IR spectrum reading. Data/Observations: Add 400 µL of Octene 1M od borane-tetrahydrofuran complex added slowly over 5 minutes, placed on hot plate and heated Stirred 45 minutes at room temperature 10 drops distilled water then added slowly 0.5ml of hydrogen peroxide drops added over 40 seconds Mixture heated at kept at 45 degree C for 1 hour Hydrochloric acid drops added to separatory funnel Separated and product dried Product filtered and air used to evaporate the ether Vial before product: 4.233 g Vial after product: 4.532g Micropipette set to 20 microliters, methylene chloride added to clean vial and then placed in GC tube for reading IR Spectrum Reading

GC reading

Calculations/Results: Percent Yield: 0.400ml Octene x 0.72 (g/ml) = 0.288g 0.288%𝑔%𝑜𝑐𝑡𝑒𝑛𝑒 = 0.00257%𝑚𝑜𝑙𝑠 112.2%𝑔/𝑚𝑜𝑙 2.0 ml BH3-THF x 0.898 g/mol=1.796 g 1.796𝑔 = 0.0217%𝑚𝑜𝑙𝑠 82.92%𝑔/𝑚𝑜𝑙 Total mols reacted: 0.02427 Product: Vial with product: 4.532g- vial without product 4.233g= 0.299g

0.299𝑔 130.3𝑔 = 0.00229%𝑚𝑜𝑙𝑠 𝑚𝑜𝑙 !.!!##$%&'()%*+',-./ Percent Yield: 𝑥%100% = 9.45%% !.!#0#1%&'()%+23./34/ Discussion/Conclusion In this experiment, an alkene was converted to an alcohol. This reaction follows the antiMarknovinikov pathway so even though two products are possible (1-octanol or 2-octanol) 1octanol will be expected as the major product due to the pathway followed. In the IR spectrum obtained a strong, broad peak is seen at 3300-3600 cm-1 indicating the reaction was a success and 1-octanol was the major product obtained. A GC spectrum can also determine what is in the product and how pure the product is. 1-octanol and 2-octanol only contain 2 peaks in their GC. The addition of other peaks hints that the product was not pure 1-octanol but also contained 2octanol and some octan-1-ene. The peak close to 3 indicates 1-octanol and the additional peak close to 2 indicates 2-octanol. Post Lab Questions: 1. What should you observe in the IR spectrum of your product as evidence of a successful reaction? What would you look for in the IR spectrum that would indicate un-reacted starting material? A strong broad peak at 3300-3600cm-1 will appear and peaks at 1600cm-1 and 3000cm-1 will disappear. 2. If this reaction was performed with 2-methylbut-2-ene rather than 1-octene what should be the major product? If 2-methylbut-2-ene was reacted with aqueous sulfuric acid what should the major product be? A reaction with 2-methylbut-2-ene would produce 3-methylbutan-2-ol A reaction of 2-methylbut-2-ene with H2SO4 would produce 2-methylbutan-2-ol 3. You needed to make sure your glassware was dry before proceeding with the hydroboration reaction and an excess of hydroborane was used to counter the small amounts of water present in the reaction. Why is the borane-THF reagent so reactive with water? Hint: What is the electronegativity of B compared to H? B is slightly electropositive in this substance and H is slightly electronegative. Therefore water molecules will rapidly attack the B atom. Therefore the BH3-THF regent will be more reactive in water 4. What might be a source of octane in the product mixture in this reaction? Hint: You did quench the hydroboration reaction with water and let the mixture sit for a week before proceeding to the oxidation step.

Water prevented the reaction from continuing so water reacted with alkyl boron in hydrolysis reaction which produce octane....