amines, amino acids and proteins

an amine is an organic compound derived from ammonia in which one or more hydrogen atoms have been replaced by a carbon chain or ring

an aliphatic amine has the nitrogen atom attached to atleast one straight or branched carbon chain

aromatic amines have the nitrogen atom attached to an aromatic ring

• intermediates in the production of dyestuffs , explosives and drugs • amines and derivatives are used as drugs to treat malaria and sleeping sickness • amines are used to make some plastics eg . nylon • fish oils contain amines • carboxylic acids with amine groups are called amino acids • quaternary amine salts are used in detergents

• alkyl chain attached is a prefix and add amine after eg - methylamine • unless nitrogen atom is attached elsewhere on the chain of the alkyl group eg carbon 2 then it becomes 2- amino (alkyl) eg 2-aminobutane

• if they have the same alkyl group we use di + alkyl group + amine eg dimethylamine -with different groups N is used and it is named as an N substituted derivative of the larger group so first we name normally with larger group eg propylamine and then add N- alkyl eg N-methylpropylamine ( it is not in alphabetical order )

• if it is the same group we use tri + alkyl group eg trimethylamine • if it is different groups we look for the longest chain , then we order the next two alkyl groups alphabetically using N,N eg N-ethyl,N-methylpropylamine

they have a lone pair which means they can accept protons , when they accept a proton , a dative covalent bond is formed between the nitrogen atom and the proton

• an ion is formed • to name we add ammonium ion to the origonal name

a salt of the amine is formed

methylammonium chloride (CH3NH3+Cl-)

methylammonium sulphate (CH3NH3+)2 SO42-

• gentle warming with a halogenoalkane • excess concentrated ammonia (NH3) -use ethanol -nucleophillic substitution • produces an ammonium salt which we then react with NaOH to deprotonate and generate the amine • this produces water and NaCl

• reduces further substitution of the amine group and formation of secondary and tertiary amines

to prevent any substitution of the haloalkane by water to produce alcohols

ammonia has a lone pair of electrons and therefore can act as a nucleophile

we use the primary amine formed which will still contain a lone pair of electrons so can attack the carbon on another halogenoalkane to produce a salt which is then deprotonated

• the secondary amine produced still contains a lone pair of electrons so can attack another halogenoalkane

• reduction of nitrobenzene using tin and concentrated HCl ( conc. hcl and sn) heated under reflux to form the ammonium salt which is then reacted with excess sodium hydroxide to form the aromatic amine phenylamine

• ammonia reacts much more slowly with chloroarenes than chloroalkanes • ammonia is a nucelophille and the delocalised pi eletron cloud of a chloroarene repels the lone pair of an approaching ammonia molecule • also the c-cl bond is stronger in the chloroarene due to delocalisation of electron density from the ring with the bond

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• a basic amine group -an acididc carboyxl group

• amine group and carboxyl group are attached to the same carbon atom

RCH(NH2)COOH