Chapter 28.1 Flashcards
Why are reactions that form carbon-carbon bonds important?
They provide a means of synthesising new compounds containing a longer carbon chain.
What is the nitrile group?
-CN, an organic functional group
How can nitriles be formed from haloalkanes?
Haloalkanes react with sodium cyanide, NaCN, or potassium cyanide, KCN, in ethanol.
What process happens when nitriles are formed from haloalkanes?
Nucleophilic substitution
Why is the reaction of haloalkanes with sodium cyanide, NaCN, in ethanol important?
The length of the carbon chain is increased.
What would happen to 1-chloropropane when reacted with sodium cyanide, NaCN, in ethanol?
Butanenitrile (CH3CH2CH2CN) would be formed.
How do aldehydes and ketones react with hydrogen cyanide (HCN)?
In a nucleophilic addition reacion.
What are the two ways a carbon chain can be lengthened (not involving aromatic compounds)?
Haloalkanes react with sodium cyanide, NaCN, in ethanol.
Aldehydes/ketones react with HCN.
What happens when aldehydes/ketones react with HCN?
The length of the carbon-carbon chain is increased.
What is a carbonyl compound?
An aldehyde of ketone
What is the product of an aldehyde/ketone reacting with hydrogen cyanide (HCN)?
A hydroxynitrile (previously called cyanohydrin)
Why is sodium cyanide (NaCN) and sulphuric acid (H2SO4) used instead of hydrogen cyanide to react with aldehyde/ketone?
Hydrogen cyanide (HCN) is too poisonous but an increased reaction rate is obtained in the presence of cyanide ions. Using sodium cyanide (NaCN) and sulphuric acid (H2SO4) increases the reaction rate while still improving safety.
What are nitriles useful for?
They are useful intermediates in the synthesis of other organic compounds such as amines and carboxylic acids.
How can nitriles be reduced?
By the nitrile reacting with hydrogen in the presence of a nickel catalyst.
How do nitriles undergo hydrolysis?
The nitrile is heated with dilute aqueous acid (e.g. HCl (aq)) to form carboxylic acids.
What is alkylation?
A reaction that transfers an alkyl group from a haloalkane to a benzene ring.
What are the two ways a carbon chain can be added to a benzene molecule?
Alkylation and acylation
How does alkylation take place?
The reaction takes place in the presence of a Friedel-Crafts catalyst such as aluminium chloride.
What does the ‘ethylation of benzene’ mean?
A benzene molecule reacts with a haloalkane to form ethylbenzene, for example.
What is acylation?
A reaction where benzene reacts with an acyl chloride (e.g. C2H5COCl) and an aluminium chloride catalyst (AlCl3) to synthesise a ketone.
Why is acylation useful?
Because the product of acylation will undergo the typical reactions of a ketone.