Orgo 2 Reactions Unit 3

Show the mechanism for an aldol rxn

Show the mechanism for a Claisen rxn

Draw what pyridine and imidazole look like.

What are 3 previously learned ways to make an amine?

• SN2 rxn with ^-CN

• Reduction of an amide using 1. LiAlH₄ 2. H₃O⁺

• Nitration of an aromatic (HNO₃, H₂SO₄) and then reduction (H₂, Pd/C or Fe, H₃O⁺, ^-OH)

How to create and amine using azide?

SN2 rxn of alkyl halide with sodium azide, NaN₃

Followed by reduction with 1. LiAlH₄ 2. H₃O⁺

Can you mono brominate an aromatic ring if it has an amine on it?

No, it will OVER activate the ring and you will get a heinous mixture

Can you do Friedel Crafts alkylation or acylation with -NH₂ on the ring?

NO

What is a workaround for this?

React the aniline with an acyl chloride or other to form an amide, then do the desired EAS (will add ortho/para) then hydrolyze back to get the newly substituted ring

What is needed for the Gabriel amine synthesis?

Start with pthalimide

1. KOH

2. Primary alkyl halide

3. NaOH, H₂O, heat (acyl sub hydrolysis)

Show the mechanism for a Michael addition (1,4)

What are the requirements for a Dieckmann rxn to occur (Michael addition + aldol)

1,5 dicarbonyl after 1,4 addition

Proton on an alpha carbon that would form a 6-membered ring

Draw pyridine and imidazole

How to form an amine from an alkyl halide?

SN2 using NaN₃ and then reduce

What happens if you try to do SN2 on an alkyl halide with NH₃ (ammonia)?

Will give quarternary ammonium salt with positive charge

What happens if you try to monobrominate aniline?

Will get a heinous mixture of mono, di, tri-brominated products because the ring is overactivated

What is a workaround for this?

Aryl amine → Amide (use anhydride and pyridine) → do desired EAS → acyl sub back (hydrolysis)

Can you do Friedel Crafts with an amine on the ring?

NO

Show the overall rxn and steps for the Gabriel Amine Synthesis

Good for making amine from a primary alkyl halide (could also use sodium azide though)

What is needed for the Hoffman rearrangement and what are the products?

Start from primary amide

Use NaOH, Br₂, H₂O

Remove carbonyl (including carbon) to yield primary amine and CO₂

What is needed for the Curtis rearrangement and what are the products?

Start from acyl azide

Use H₂O and heat

Yield primary amine, CO₂, and N₂

What are the 4 steps to make a diazonium salt?

1. HNO₃, H₂SO₄ (nitration)

2. H₂, Pd/C or 1. Fe, H₃O⁺ 2. ^-OH (reduction)

3. HNO₂, H₂SO₄ (diazotization)

4. Substitution

What are options for the 4th substitution step?

To add Br → HBr, CuBr, heat

To add Cl → HCl, CuCl, heat

To add OH → H₂O, H₂SO₄, heat

To add CN → KCN, CuCN, heat

Show the mechanism for diazonium coupling.