Amines, amides and polyamides Flashcards
What is the amine functional group?
primary: R-NH2
secondary: R-NH-R
Tertiary R-N(R)-R
How are amines named?
____yl #-amine
eg. propyl 2-amine
Describe intermolecular bonding in amines.
London forces, permanent dipoles and hydrogen bonds between the lone pair on N and delta + hydrogen atoms
Why are amines weak bases?
They can accept protons to form alkyl ammonium salts
How do amines accept protons?
The lone pair on the nitrogen atom can form a dative covalent bond with an H+ ion.
How can ammonia act as a nucleophile?
By donating the lone pair on the nitrogen atom
How are primary amines prepared?
By nucleophilic substitution onto haloalkanes
Give a general equation and conditions for the production of primary amines
haloalkane + excess ammonia —–> primary amine + hydrogen halide
Ethanol cosolvent
How can phenylamines be synthesised?
By the reduction of nitrobenzene
Give equations for the two steps for the synthesis of phenylamine from nitrobenzene.
Nitrobenzene + 6[H] + HCl ——> phenyl ammonium chloride + 2H20
Phenyl ammonium chloride + NaOH ——> Phenyl amine + H20 + NaCl
Give the conditions for the reduction of nitrobenzene to phenyl amine
Step 1: Sn catalyst and conc HCl
Step 2: NaOH in excess
How is nitrobenzene synthesised?
The electrophilic substitution of NO2+ onto an aromatic ring
How is the electrophile formed for the formation of nitrobenzene.
H2SO4 + HNO3 —–> NO2+ + HSO4- + H20
What are the conditions for the nitration of benzene?
50 degrees C
Conc nitric acid
Conc sulphuric acid
Which two funtional groups are present in amino acids?
Amine -NH2
Carboxylic acid -COOH
How do amino acids react with an acid?
The NH2 group accepts a proton to form a salt.
How do amino acids react with hydroxide ions?
The carboxylic acid -OH group donates an H+ ion to form water.
How do amino acids react with alcohols?
They form aminoesters
What is the functional group of an amide?
CONH2
A carboxylic acid derivative with an NH2 group instead of an OH group
How is a primary amide synthesised?
The reaction of an acyl chloride with ammonia.
Give a general equation for the formation of primary amides.
acyl chloride + 2NH3 ——> primary amide + NH4Cl
How is a secondary amide synthesised?
The reaction of an acyl chloride with a primary amine
Give a general equation for the formation of secondary amides.
acyl chloride + 2 primary amine —–> secondary amide + alkylammonium chloride
What are the three types of structural isomers?
Chain- different numbers or positions of side chains on the main carbon chain
Positional- the functional group is in a different position on the carbon chain
Functional group- the functional group is different
