Organic Chemistry, Unit 14- Learning aim A

Unit 14: Applications of Organic Chemistry
Learning aim A: Understand the structures, reactions and properties of functional group compounds.


Assignment title: Functional group chemistry for designer molecules
Functional groups and their relevance to reactivity of organic compounds
Functional groups are groups of bonded atoms. They are often used to give physical and chemical
properties to a compound, cause the same kind of reaction no matter the compound. This allows to
distinguish similar compounds from each other. Reactivity may get limited due to specific functional
groups.
Unsaturated alkyls chains have higher reactivity and saturated alkyls chains have a low reactivity. The
alkyl chains tend to be unreactive. This is when functionalization takes place, to add properties to
these unreactive chains.
P1: Reactions of range of carbonyl and non-carbonyl functional group compounds

• Nucleophilic substitution of aq sodium hydroxide
Balanced Equation: C2H5Br +NaOH —> C2H5OH + NaBr

• Nucleophilic substitution of Potassium cyanide
Balanced equation: C2H5Br + KCN —> C2H5CN + KBr

• Nucleophilic substitution of Ammonia
Balanced equation: 1) C2H5Br + NH3 —> C2H5NH2 + HBr
2) HBr + NH3 —> NH4Br
Equation 2, excess ammonia, ensures that salt does not get formed through the removal of HBr in the
products.

• Nucleophilic substitution of Water
Balanced equation: C2H5Br + H2O —> C2H5OH + HBr

• Halogenoalkanes and elimination
Equation: C3H7Br + NaOH —> C3H6 + H2O + NaBr

• Elimination of water (dehydration)
Equation: C2H5OH —>CH2=CH2 + H2O

• Preparation of amine
Equation: C2H5Br + NH3 --> C2H5NH2 + HBr

• Amines with Basic properties:
With H+: HOOCCH2NH2 + H+ --> HOOCCH2NH3+
With HCl: HOOCC2NH2 + HCl --> HOOCCH2NH3+CL-

• Amines with Acidic properties:
With OH-: HOOCCH2NH2 + OH- --> -OOCCH2NH2 + H2O
With NaOH: HOOCCH2NH2 + NaOH --> Na+-OOCCH2NH2 +H2O

• Nucleophilic substitution with amines

,Unit 14: Applications of Organic Chemistry
Learning aim A: Understand the structures, reactions and properties of functional group compounds.


2° amine, diethylamide: C2H5NH2 + C2H5Br --> HBr + (C2H5)2NH
3° amine, triethylamine: (C2H5)2NH + C2H5Br --> HBr + (C2H5)3N
4° amine (quaternary salt), tetraethylammonium bromide: (C2H5)3N + C2H5Br --> (C2H5)4N+Br-

• Aldehydes and ketones and oxidation
Aldehydes: RCH + [O] —> RCOOH
CH3CHO + [O] —> CH3COOH
Ketones: C2H5COCH2CH3 + 3[O] —> C2H5COOH +CH3COOH

• Aldehydes and ketones and reduction
Equations: CH3CHO + 2[H] --> CH3CH2OH
CH3COCH3 + 2[H] --> CH3CHOHCH3

• Aldehydes and ketones and reduction with the reagent hydrogen
Equations: CH3CHO + 2[H] --> CH3CH2OH
CH3COCH3 + 2[H] --> CH3CHOHCH3
The hydrogen in the equation reduces the C=C bonds.

• Aldehydes and ketones and nucleophilic addition
Equation: CH3CHO + HCN —> CH3CH(OH)CN (2-hydroxypropanenitrile)
The HCN in the reactants is weak and because of this it struggles to dissociate itself into ions. Using
the KCN which is ionic will produce more nucleophilic CN-.
HCN ⇌ H+ + CN-

• Acyl chlorides formation
Equation: CH3COOH + SOCl2 --> CH3COCl + SO2 + HCl

• Acyl chlorides and addition-elimination
When acyl chloride reacts with water
Equation: CH3COCl + H2O --> CH3COOH + HCl
When acyl chloride reacts with alcohols
Equation: CH3COCl + CH3OH --> CH3COOCH3 + HCl
When acyl chlorides react with ammonia
Equation: CH3COCl + NH3 --> CH3CONH2 + HCl
Equation II: CH3COCl +2NH3 --> CH3CONH2 + NH4Cl

• Amide's preparation
Equation: CH3COCl + NH3 --> CH3CONH2 + HCl.

• Amides and its chemical properties

, Unit 14: Applications of Organic Chemistry
Learning aim A: Understand the structures, reactions and properties of functional group compounds.


General reaction for hydrolysis of amides: CH3CONH2 + H2O --> CH3COOH + NH3
Acidic solution for hydrolysis of amides: CH3CONH2 + H2O + HCl --> CH3COOH + NH4Cl
Alkaline solution for hydrolysis of amides: CH3CONH2 + NaOH --> CH3COONa + NH3
M2: Plan a multi-step synthesis of carbonyl and non-carbonyl organic molecules
Halogenoalkanes
Halogenoalkanes are like saturated hydrocarbons but with one or more of the hydrogen atoms
replaced with a halogen (fluorine, chlorine, bromine or iodine). the reactivity of a molecule depends
on the degree of the carbon that is bonded to the functional group. They are classified according to the
environment of the halogen. Primary has a high activation energy and tertiary has a much lower
activation energy.
Primary halogenoalkanes
In primary halogenoalkanes the carbon with the halogen has one alkyl to it. Mostly undergoes
nucleophilic substitution.




Secondary halogenoalkanes
In secondary halogenoalkanes the carbon with the halogen has two alkyls to it. These halogenoalkanes
can undergo both nucleophilic substitution and elimination.




Tertiary halogenoalkanes
In tertiary halogenoalkanes the carbon with the halogen has three alkyls attached to it. Mostly
undergoes elimination.