Acyl Chlorides & Acid Anhydrides Flashcards
What are acyl chlorides?
Acyl chlorides are carboxylic acid derivatives where the OH group is replaced by a Cl
How are acyl chlorides made?
Acyl chlorides are made by reacting carboxylic acids with thionyl chloride, SOCl2.
Carboxylic acid + thionyl chloride -> Acyl chloride + SO2 + HCl
What is the equation for the reaction of propanoic acid into an acyl chloride?
CH3CH2COOH + SOCl2 -> CH3CH2COCl + SO2 + HCl
Why must water not be present when forming an acyl chloride?
Water must not be present or the newly formed acyl chloride will react with it to form a carboxylic acid.
What is the equation for propanoyl chloride into a carboxylic acid?
CH3CH2COCl + H2O -> CH3CH2COOH + HCl
What can acyl chlorides be used to make?
Esters (including phenyl esters)
Carboxylic acids
Primary and secondary amides
In general, what happens when an acyl chloride reacts?
The Cl is substituted, and the Cl joins with a H to form HCl
How do you make an ester from an acyl chloride?
Acyl chloride + alcohol -> ester + HCl
How do you make a phenyl ester?
Acyl chloride + phenol -> phenyl ester + HCl
How can you make a primary amide from an acyl chloride?
Acyl chloride + ammonia -> Primary amide + HCl
How do you make a secondary amide from an acyl chloride?
Acyl chloride + amine -> secondary amide + HCl
How is an acid anhydride formed?
Acid anhydrides are formed from the dehydration reaction of two carboxylic acid groups.
General formula of acid anhydrides
RCOOCOR
Give the name for the molecule with the formula (HCO)2O
methanoic anhydride
acid anhydride + alcohol ->
ester + carboxylic acid