Prepartion of amines Flashcards
How are primary alphatic amine be prepared?
- ammonia reacting with halogenoalkanes
- nucleophillic substition
- from reduction of nitriles
- cyanide ion substitutes the halogen (nucleophillic substition) forming a nitrile
- nitrile reduced to a primary amine
How is the nitrile produced
halogenalkanes react with cyanide ion in an aqueous ethanol
the cyanide ion replaces the halide ion by nucleophlic substitution to form a nitrile
RBr + CN- → R-C≡N + Br-
How is the amine formed from the nitrile
nitriles contain the functional group -C≡N
they can be reduced to primary amines
R-C≡N + 2H2 → R-CH2NH2
nickel / hydrogen catalyst
Why is reduction of nitriles used over the reaction of bromoalkane and ammonia?
- purer product
- carbon chain of the product is onbe carbon longer than in the starting material
What is phenylamine and what are its uses?
the simplest arylamine
starting point for many other chemicals
How is phenylamine produced?
- from benzene
- nitrobezene produced
- then reduced to phenylamine
How is nitrobenzene produced
benzene is reacted with a mixture of concentrated nitric acid and concentrated sulfurice acid
this produces nitrobenzene
How is phenylamine made from nitrobezene
nitrobenzene is reduced to phenylamine, using tin and hydrochloric acid as the reducing agent
the tin and HCl react to form hydrogen, which reduces the nitrobenzene by removing oxygen atoms of the NO2 group and replacing them with hydrogen
C6H5NO2 + 6[H] → C6H5NH2 + 2H2O
What is formed in the phenylamine reaction?
the salt C6H5NH3 +Cl- is formed as it is carried out in HCl
sodium hydroxide is added to liberate the free amine
C6H5NH3 +Cl- + NaOH → C6H5NH2 + H2O + NaCl
What is the reducing agent to convert nitrobenzene to phenylamine
Sn / HCl
Name and draw the mechanism for forming amides
What are the products and reactants
HCl eliminated - hence addition-elimination
What are the used of amides?
important reaction in forming polymers such as nylon
