Amides Flashcards Preview

Organic chemistry and synthesis A2 > Amides > Flashcards

Flashcards in Amides Deck (19):

What are the 3 ways of converting a carboxylic acid to an amide?

From the acid chloride

From dehydration of ammonium salt

From an ester (reacts with NH3)


A carboxylic acid can be converted to an amide, give one way in which this can be done

From the acid chloride

Convert acid to acid chloride via SOCl2, reflux and dry conditions

Then add dry or concentrated NH3 to the acid chloride to produce an amide and HCl - NUCLEOPHILIC sub in both


Why would the NH3 used in converting acids to amides via acid chlorides need to be dry or concentrated?

Otherwise hydrolysis would occur and the acid chloride would hydrolyse back to the acid


Another way to convert acid to amide is by dehydration of ammonium salt- explain how this works

First add excess acid and reflux with ammonium carbonate to form an ammonium salt

Acid + carbonate -- > salt + CO2 + H2O

Ammonium salt then dries on heating to produce amide and H2O


Describe acid hydrolysis

Amide via water,
hydrochloric acid
and reflux

To produce a carboxylic acid and NH4Cl


Describe alkaline hydrolysis

2 steps

Step 1 - amide via water sodium hydroxide and reflux to produce sodium salt and ammonia

Salt is then converted to an acid by adding hydrochloric acid


Describe the reduction of primary amides

Use LiAlH4 - dry solvent, room temp

This will form a primary AMINE


What bonding occurs between amide molecules?

What is its bonding stronger than?

Amides have hydrogenbonding - it's stronger bonding than that in carboxylic acids so amides have higher MP AND BP when comparing molecules of similar molecular size


Describe the solubility of amides I

Amide are soluble in water due to hydrogen bonding
Solubility decreases as hydrocarbon chain length increases and the polar affect of the amide group Decreases


Describe the melting points and boiling points of amides

Melting point and boiling point of amides increase as the hydrocarbon chain length increases due to an increase in van der waals between molecules


Define condensation polymerisation

1 large molecule is formed (polymer) and one small molecule lost e.g water, this means the atom economy is less than 100%. 2 functional groups needed in the monomers


Define addition polymerisation

Only 1 large molecule formed and no molecules lost so atom economy is 100%- only 1 functional group needed in each monomer- c=c e.g polythene ---> ethene


How are polyesters made?

By a condensation polymerisation reaction- small molecule eliminated or produced, if small molecule is water than it's also called dehydration


Nylon-6,6 monomers produce a polymer in what kind of reaction?

The polymer is made from a condensation reaction - condensation polymer- a small molecule is produced or eliminated in this


Why are nylons classed as poly amides/polypeptides?

Because the linkage between the monomers is the amide/peptide link


Draw monomers that create Nylon-6,6 and itself



Draw monomers that create polyamide Kevlar and itself



Draw monomers that make polyester terylene PET and itself



How is 1,6-diaminohexane (used in production of nylon-6,6) made?

By the reduction of a nitrile (NC(CH2)4CN) using LiAlH4 anhydrous via [8H]