Organic III Reactions

Question 1

How to make a primary amine?

Answer 1

• react a halogenoalkane with ethanolic ammonia in a sealed tube
• ammonia acts as a nucleophile
• also producing ammonium salt

Question 2

How to form a primary amine via reduction?

Answer 2

• reduce a ntrile
• using hydrogen and a nickel catalyst
• requires high temperature and pressure
• can also use LiAlH4 in dry ether as a reducing agent with a dilute acid

Question 3

Reagents and conditions for forming an aromatic amine?

Answer 3

Step 1- heat a nitro compound (e.g nitrobenzene) under reflux
- with concentrated HCl and tin catalyst to form a salt
Step 2- react the salt with an alkali e.g sodium hydroxide

Question 4

Describe how amines react in a neutralisation reaction?

Answer 4

• amines are bases so are neutralised by acids
• forming ammonium salts
• e.g: butylamine + HCl —> butylammonium chloride

Question 5

Describe the reaction of amines in water

Answer 5

• small amines dissolve in water
• forming alkali solutions
• producing alkylammonium ions and hydroxide ions

Question 6

How to form N-substituted amides from an acyl chloride?

Answer 6

• react primary amine with an acyl chloride
• also forms HCl

Question 7

Describe the reactions of butylamine with copper(II) sulfate

Answer 7

• add a small amount of butylamine to form a pale blue precipitate [Cu(OH)2(H2O)4]
• add excess butylamine to form a deep blue solution [Cu(C4H9NH2)4(H2O2)2]^2+

Question 8

How to form an primary amide from an acyl chloride?

Answer 8

• react acyl chloride with ammonia
• also forms HCl
• must be at room temperature

Question 9

How to form an N-substituted amide?

Answer 9

• react a primary amine with an acyl chloride
• also forms HCl

Question 10

Describe how to form phenylketone from benzene

Answer 10

• acylation
• must be done under reflux with dry ether
  1 - react acyl chloride with AlCl3 to form RC=O+ electrophile and AlCl4-
  2 - benzene reacts with RC=O+ to via electrophilic substitution to form a phenylketone and H+
  3 - AlCl4- + H+ –> AlCl3 + HCl

Question 11

Describe how to form an alkylbenzene from benzene, include reagants and conditions

Answer 11

• alkylation
• must be done under reflux with dry ether
  1 - react halogenoalkane with AlCl3 to form R+ electrophile and AlCl4-
  2 - benzene reacts with R+ via electrophilic substitution to form alkylbenzene and H+
  3 - AlCl4- + H+ –> AlCl3 + HCl

Question 12

Describe how to form nitrobenzene from benzene, include reagants and conditions

Answer 12

• nitration
• must be below 55 degrees
  1 - conc HNO3 + conc H2SO4 –> NO2+ + H2O + HSO4-
  2 - benzene reacts with NO2+ to form nitrobenzene and H+
  3 - HSO4- + H+ –> H2SO4

Question 13

Describe how to form a halobenzene from benzene

Answer 13

• halogenation
• for example
  1 - AlCl3 + Cl2 –> Cl+ + AlCl4-
  2 - benzene reacts with Cl+ to form chlorobenzene + H+
  3 - AlCl4- + H+ –> AlCl3 + HCl

Question 14

What forms from phenol + alkali?

Answer 14

• a salt (sodium phenoxide) and water

Question 15

What forms from phenol and bromine water?

Answer 15

2,4,6-tribromophenol and 3HBr

Question 16

How to form TCP?
( 2,4,6-trichlorophenol)

Answer 16

• react phenol with 3Cl2
• also forms 3HCl

Question 17

What forms from phenol + dilute nitric acid?

Answer 17

2-nitrophenol
4-nitrophenol

Question 18

what forms from phenol + metal?

Answer 18

• a salt + 1/2H2