26.4 - Carboxylic Acid Derivatives Flashcards Preview

OCR A Chemistry A Level - Chapter 26 > 26.4 - Carboxylic Acid Derivatives > Flashcards

Flashcards in 26.4 - Carboxylic Acid Derivatives Deck (6)
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1

What is a carboxylic acid derivative?

A compound that can be hydrolysed to form the PARENT CARBOXYLIC ACID

All derivatives have an acyl group

 

2

What are the 4 carboxylic acid derivatives?

Characteristics, naming

  • ESTERS
    • suffix -oate
    • alkyl on the -O of the -COO is the prefix
  • AMIDES
  • ACID ANHYDRIDES
    • formed by the removal of H2O from 2 carboxylic acids
  • ACYL CHLORIDE

3

Describe the process of esterification.

alcohol + carboxylic acid → ester

  • alcohol warmed with CA & conc. H2SO4

alcohol + acid anydride

gives ester carboxylic acid 

R'OH + (RC(O))2O → RCOOR' + RCOOH

4

Describe the 2 ester hydrolysis reactions.

Ester hydrolysed by either an acid or an alkali

ACID HYDROLYSIS (reverse esterification)

ester + water <> parent CA + alcohol 

1. Heat ester under reflux with dilute aqeous acid 

2. Ester broen down by water, acid is catalyst

ALKALI HYDROLYSIS (saponification)

Ester heated under reflux with aq OH- ions

forms carboxylate salt + alcohol

IRREVERSIBLE

 

 

 

5

What are the acyl chloride reactions?

  • CA + SOCl2 → acyl chloride + SO2 + HCl
    • ^ Preparation of acyl chloride from parent carboxylic acid
  • Acyl chlorides are usefule - as they are easily converted to CA derivatives
  • acyl chloride + alcohol → ester
    • acyl chloride + phenol → ester
  • acyl chloride + water → carboxylic acid
  • acyl chloride + ammonia (AMINEs) → amides
    • gives a 1o amide
    • nucleophile of ammonia donates lone pair from nitrogen

 

6

What are acid anhydride reactions?

The same as acyl chlorides (+ alcohols; phenol; water; ammonia; amines) 

Less reactive than acyl chloride