C27 Amines, Amino Acids, And Polymers Flashcards
How do you name amines?
-amine or amino-
Why are amines so reactive?
The lone pair of electrons on the Nitrogen - due to the polar N-H bond
What shape are amines around the N? Bond angle?
Trigonal Pyramidal
107*
Due to lone pair on N
What kind of IMF do they have and why?
Hydrogen bonding
Due to polar N-H bond and lone pair of electrons on N atom.
Do amines have intermolecular forces which are stronger than or weaker than alcohols? Why?
Weaker
As N has a lower electronegativity than O
So it therefore has weaker hydrogen bonding
How can/when do amines act as bases?
The lone pair on the Nitrogen accepts a proton
How can/when do amines act as nucleophiles?
When they bond with an a electron-deficient C atom (donate lone pair from N)
What is the product from the basic action of an Amine with water?
RNH3+ - ammonium ion, which forms a salt with an anion
In order to be the strongest base, what must a particular amine have (out of a set of amines)?
Greatest electron density around the N atoms, making it a better electron pair donor (attracts protons more)
What effect do Alkyl groups have (on electron density and base strength)?
Positive inductive effect - increase electron density around N -> stronger base
Place the following in order of base strength (in general): NH3, primary amine, secondary amine, phenyl amine
Secondary amine > primary amine > NH3 > Phenyl amine
How can primary amines form secondary and tertiary and 4* ammonium ions?
Multiple substitutions: primary amine is a nucleophile that attacks the original haloalkane ETC
Problems with this method= not efficient as low yield of 1* amine due to multiple substitutions
( how can 1* amines form 2,3 and 4* ammonium ions?
Multiple substitutions: primary amine is a nucleophile that attacks the original haloalkane etc)
What are the problems with this method?
Not efficient as low yield of 1* amines due to multiple substitutions
How would you maximise the yield of the primary amine?
Use excess ammonia
What type of mechanism is the reaction of a haloalkanes with a Cyanide ion?
Nucleophilic substitution
What type of mechanism is the reaction of a haloalkanes with a Cyanide ion?
Nucleophilic substitution
What conditions does the reaction of a haloalkane with a cyanide ion require? What is the product formed?
Ethanol as a solvent
A nitrile is formed
How do you get from a nitrile to a primary amines? (Reaction type, reagent and catalysts)
Reduction reaction
Using Nickel
Hydrogen catalyst
Why’s this a purer method of synthesising amines?
Only the primary amine can be formed
Why is the reduction reaction of a nitrile with Nickel using a purer method of synthesising amines?
Only the primary amine can be formed.
What conditions are needed to form Nitrobenzene from Benzene?
Concentrated H2SO4 and HNO3 to form the NO2+ ion for electrophilic attack.
How do you from an ammonium chloride salt from nitrobenzene? What conditions are needed?
Reduce the Nitrile using TIN/HCl -> forms an ammonium salt with Cl- ions
Room temperature
What mechanism is used for forming Amides from acyl chlorides and amines?
Nucleophilic addition/elimination
What are the 2 functional groups of amino acids?
NH2 and COOH (amine and carboxylic acid)
Are alpha amino acids chiral? Why?
Yes, one carbon has 4 different substituents. Except glycine, where R = H
