Amines

Question 1

Classification of amines is different in what way

Answer 1

Amines are classified by how many carbons are attached to the nitrogen group directly.

Question 2

How do you name an amine?

Answer 2

-amine
#where N attaches
Substituents on N have N prefixes, not numbers

Question 3

What are all quaternary amines?

Answer 3

Ammonium salts

Question 4

Why is there no chirality at nitrogen when it’s bonded 3 times and has a lone pair, even though it is sp3?

Answer 4

Because nitrogen is always sp3 with one lone pair, nitrogen can undergo inversion with its lone pair and enantiomers easily interconvert.

Question 5

What does nitrogen require for chirality?

Answer 5

Four bonds or can be a cyclic amine

Question 6

Describe amines boiling points

Answer 6

Lower than corresponding alcohols because of less polarity

Tertiary less than primary because no hydrogen bonding

Question 7

Describe solubility

Answer 7

Less than 6 carbons = soluble in water

Branching increases solubility

Question 8

Ammonia

Answer 8

Nh3

Question 9

Basicity

Answer 9

Alkyl amines more basic than ammonia

Question 10

Reactivity

Answer 10

Lone pair can act as nucleophile or base

Creates another bond with carbon or protonates the amine

Question 11

Does an alkyl group stabilize or destabilize an amine?

Answer 11

Stabilize

Question 12

How do you create an ammonium salt and what are its new properties?

Answer 12

Protonate the amine

• higher melting point as ionic solid
• no fishy odor
• water soluble

Question 13

Briefly explain how to purify an amine

Answer 13

Mix amine with ether and water. Remove water and add hcl. Remove ether phase. Add base, then add fresh ether.

Question 14

Reaction of amine with carbonyl group

Answer 14

H+ -> intermediate loses H20 - N creates double bond with C - N loses all hydrogen, keeps lone pair

Question 15

Alkylation of Amine

Answer 15

Ammonium salt leaves to pair with halide, takes a H from amine

Question 16

Acylation of Amine

Answer 16

H leaves amine with Cl

Question 17

Reductive Amination - creation of 2* amine

Answer 17

Condensation creates n-substituted imine

Reduction creates 2* Amine

Question 18

Reductive amination - 3* Amine

Answer 18

Condensation w 2* Amine creates iminium salt

Reduction w LAH creates 3* Amine

Question 19

Synthesis of primary amine

Answer 19

Acid chloride + Ammonia

Then reduce + hydrolysis

Question 20

Synthesis of 2* Amine

Answer 20

Acid chloride + Amine

Reduction + hydrolysis

Question 21

Synthesis of 3* Amine

Answer 21

Acid chloride + 2 Amine

Reduce + hydrolysis