Amines - Amides- Amino Acids + Protiens

Question 1

Amines

Answer 1

Stem of -yl or end in amine.

NH2 Group

If the amine is secondary with two alkyl groups attached to N, then the smaller group is proceeded by a -N

Amino may be used if there i another priority functional group

Question 2

Aminde

Answer 2

NH2 and Double O attached to carbon

Secondary/Tertiary may have N- to identify the smaller chain

Question 3

Smell of Amines

Answer 3

Fishy smell

Question 4

Properties of primary aliphatic Amines

Answer 4

Act as bronsted-lowery bases as lone pair of electrons on nitrogen

Stronger bases then ammonia, as alkyl groups are electron releasing, pushing electrons towards nitrogen.

Question 5

Properties of secondary aliphatic Amines

Answer 5

Stronger bases then primary, as they have more electron releasing alkyl groups

Question 6

Properties of aromatic amines

Answer 6

Do not form basic solutions as lone pair of electrons on nitrogen deloalise with the ring of electrons in benzene, therefore N cant accept protons.

Question 7

Amines + Acids

Answer 7

Form ammonium salts
If NaOH was added (as reaction is reversible) amine will be produced again
(Watch where the positive and negative charges go on the salt!)

Question 8

Are small amines water soluble?

Answer 8

Yes
The amine group can form hydrogen bonds with water molecules
As London forces increased with bigger amines, this mean more energy is required.
Larger chains also disrupt the hydrogen bonding in water

Question 9

Amines + water

Answer 9

Small primary amines will react to form alkaline solution, producing alkyl ammonium ions and hydroxide ions.

Question 10

Are amines electrohpiles or nucleophiles?

Answer 10

Nucleophiles

Question 11

Amine + Copper(II) Ions

Answer 11

When amine is added to a copper sulfate soultion
[Cu(H20)6]2+
you will get a pale blue precipitate as the amine acts as an base taking 2H+ away from the complex forming [Cu(OH)2(H2O)4]

When added in excess the solution will get deep blue, as some ligands are replaced with the amine molecules that donate a lone pair forming dative bonds to the Cu2+ ion.

All are reversible

Question 12

Amine + Halogenoalkanes

Answer 12

Nucleophillic Substitution
Forms next amine

1. The partial neg charge goes to bromine, and the amine will attack the positive carbon.

For N-Sub

1. The partial neg goes from hydrogen to Nitrogen (On N), and the hydrogen in chain become positive, and the amine then attacks the other hydrogen.
2. Forms two compounds, one amine and one Amine+Halogen compound

Question 13

Ammonia + Halogenoalkane

Answer 13

Forms a mixture of Amines, as the amine is a nucleophile it can further react with the halogenoalkane when produced.

Heated in ethanoic ammonia

Ammonia will react twice (Watch number of hydrogen atoms)

Question 14

Amine + Acyl Chloride

Answer 14

Acylation
The H atom on amine is swapped for the acyl group RCO, producing a N-Substituted AMIDE.

The Acyl-Chloride must be added to concentrated solution of the amine, and the reaction is violent producing a solid white mixture.

Question 15

Reduction of Nitrile

Answer 15

1. Using LiAlH4 followed by dilute acid to form a primary amine
2. Nickle catalyst at high temp and pressure +Hydrogen to produce a primary amine. (Catalytic hydrogenation)

Question 16

Whats a problem with LiAlH4?

Answer 16

Sometimes too expensive for industrial use

Question 17

Reduction of Nitro Compounds

Answer 17

1. Heat nitrocompound with tin metal and conc HCL under reflux
2. This forms a salt, to get aromatic amine, ass NaOH

Question 18

Disadvantage of reduction of nirtile

Answer 18

1. KCN is toxic

2. Two step reaction = Lower yeild

Question 19

How to increase yield of making primary amine from halogenoalkanes + ammonia

Answer 19

Use concentrated ammonia as it limits further reactions.

Question 20

Acyl Chloride + ammonia

Answer 20

Primary Amide

Nucleophillic addition-elimination reaction

Question 21

Acyl Chloride + primary amine

Answer 21

N- substitued amide

Nuceleophillic addition-elimination reaction

Question 22

Type of reaction to form a poly amide

Answer 22

Condensation polymerisation reaction

Involve an ester/amide linkage

Question 23

Di-carboxylic acid + Diol

Answer 23

Poly(Ester) + water

Question 24

Di-carboxylic acid + diamine

Answer 24

Poly(Amide) + Water

Question 25

Diacyl dichloride + Diol

Answer 25

Poly(Ester) + HCl

Question 26

Diacyl dichloride + diamine

Answer 26

Poly(Amide) + HCl

Question 27

Zwitter ions in more acidic conditions then isoelectric point

Answer 27

NH2 is protonated

Question 28

Zwitter ions in more basic conditions then isolectlric point

Answer 28

COOH is deprotonated

Question 29

Affect of amino acids on plane polarised light

Answer 29

Most of chiral due to the 4 different groups, so light would be rotated when shone through just one enantiomer in an aqeuous soultion.

The exception is glycine where the R group is H

Question 30

Why do zwitter ions have a high melting point?

Answer 30

Ionic interactions between them.

Question 31

How to identify amino acids

Answer 31

Separate by chromatography

Calculate Rf value and compare to a know table of Rf values.

Question 32

Dipeptide

Answer 32

Two amino acids joined by a amide (Peptide) link

Question 33

Hydrolysing proteins

Answer 33

Heat in dilute acid or alkali to split into orginal amino acids.

Question 34

Esterfication with amino acids

Answer 34

The functional groups (NH2/COOH) react the same way with the other functional groups.