Chlorination of Heptane

What was the purpose of the lab? (2)

1. Demonstrate the formation of chloroheptane via the radical chlorination of heptane
2. To determine the relative reactivities primary vs secondary Hs

Chlorination of Heptane

What is the mechanism?

Chlorination of Heptane

Why is it important to not expose sulfuryl chloride to H₂O & acetone.

And why should we keep it in the hood?

1. Sulfuryl chloride reacts vigorously w/ H₂O & acetone → sulfuryl chloride gets consumed ∴ yield decreases.
2. Sulfuryl chloride is kept in the hoood as it's toxic/harmful if inhaled.

Chlorination of Heptane

What chemical rxn is occuring in the gas trap?

Write out the chemical rxn

1. Neutralization rxn
2. NaOH + HCl → NaCl + H₂O

Chlorination of Heptane

Calculate the relative reactivity of the Cl radical for 1^o, 2^o, , and 3^o Hs

Chlorination of Heptane

Why is the 2^o chloroheptane have a greater reactivity than the 1^o? (3)

1. 2^o more Hs (10) vs 1^o Hs (6)
2. 2^o radical is more stable than the 1^o radical
3. 2^o C-H bond is weaker (via inductive effect) ∴ easier to extract/break

Chlorination of Heptane

How is the GC supposed to be labeled?

Chlorination of Heptane

Perform the following calculations for this lab.

1. AY
2. TY
3. PY
4. Relative Reactivity

Important info:

• 10 mL heptane
  • Density = .6975 g/mL
  • MM = 100.21 g
• 15 mL sulfuryl chloride (SO₂Cl₂)
  • Density = 1.665 g/mL
  • MM = 134.98 g
• Mass vial = 13.13 g
• Mass vial + chloroheptane = 14.23 g
• GC provided

Diels Alder

What is the purpose? (2)

1. Demonstrate the Diels Alder reaction of E,E-2,4-hexadien-1-ol and maleic anhydride
2. Verify the formation of Diels Alder (DA) product via ¹H NMR and melting point

Diels Alder

What was the purpose of weighing the diene 1st?

it's sticky

Diels Alder

What is the purpose of using toluene for the rxn?

To allow for recrystallization. D/t toluene being nonpolar, when the solution is cooled (solubility ↓), the polar product will precipitate out & the impurities stay ∴ allowing for purification.

Diels Alder

Show how maleic anhydride is electrophilic.

Diels Alder

Assign the major IR stretches for the following compound.

Diels Alder

Complete the ¹H NMR

Diels Alder

Complete the IR

Diels Alder

Perform the following calculations for this lab.

1. AY
2. TY
3. PY

Important info:

• .4038 g maleic anhydride
  
  • MM = 98.06 g/mol
• .4023 g

Diels Alder

What was the literature mp?

156-159 ℃

Electrophilic Bromination

What is the purpose? (2)

1. Demonstrate the Electrophilic Bromination reaction of acetanilide and potassium bromate
2. Verify formation of N-(4-bromophenyl)acetamide (EB product) via ¹H NMR

Electrophilic Bromination

Provide mechanism

Electrophilic Bromination

Using resonance, show how the amide group activates the ring & directs substitution at the ortho & para positions.

Electrophilic Bromination

What is the purpose of doing this rxn at room temp?

adding heat will cause BR to form too quickly & polybrominate

Electrophilic Bromination

Identify the peaks & determine the final structure for the following rxn.

Electrophilic Bromination

Perform the following calculations for this lab.

1. AY
2. TY
3. PY

Important info:

• .2064 g acetanilide
  
  • MM = 135.16 g/mol
• .0852 g potassium bromate
  
  • MM = 167.0 g/mol
• Mass watch glass = 20.563 g
• Mass watch glass + DA product = 20.694 g

not supposed to use postassium bromate when calculating TY & PY

Electrophilic Bromination

Complete ¹H NMR

Electrophilic Bromination

Complete Mass Spec

Friedel Crafts Alkylation

What is the purpose of the lab?

1. Demonstrate the Friedel-Crafts Alkylation reaction of p-xylene and n-bromopropane
2. Verify the formation of n-propyl and iso-propyl (FC Products) via Gas Chromatogram data

Friedel Crafts Alkylation

Provide mechanism

Friedel Crafts Alkylation

Why do we use aluminum chloride (AlCl₃) in this rxn?

AlCl₃ acts as a catalyst & by binding to the E⁺ to form a complex, it increases the electrophilicity of the E⁺

Friedel Crafts Alkylation

What happens if the AlCl₃ gets wet?

AlCl₃ is very hydroscopic → gets consumed by absorbing H₂O from the atmosphere ∴ affects PY

Friedel Crafts Alkylation

Why do we use a drying tube w/ calcium chloride (CaCl₂)?

drying agent → absorbs H₂O ∴ prevents H₂O from messing up the PY

Friedel Crafts Alkylation

Why did we use a saturated NaCl solution for the extraction?

will force ions from the organic layer into the aqueous layer → clear organic & aqueous layers formed ∴ better extraction

Friedel Crafts Alkylation

Provide the mechanism, product, & labeled NMR based on the following.

Friedel Crafts Alkylation

Perform the following calculations for this lab.

1. AY
2. TY
3. PY

Important info:

• 2 mL p-xylene
  • Density = .861 g/mL
  • MM = 106.17 g/mol
• .8 mL n-bromopropane
  • Density = 1.354 g/mL
  • MM = 122.99 g/mol
• Mass watch glass = 21.30 g
• Mass watch glass + product = 22.03 g

Friedel Crafts Alkylation

What does the labeled GC look like?