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    Easy guys will someone explain to me wat the difference is between a nucleophillic substitution reaction and a nucleophillic addition/elimination reaction. Is it called a addition/elimination reaction cuz it happens in two stages first the nucleophile adds to the double bond then the other species is eliminated? :cool:
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    Hey vish...hows it going? In a nucleophilic addition/elimination reaction, a functional group is added to a molecule and water (at least i think its always water) is 'eliminated' (e.g. -COOH and -NH2 react together by addition elimination - forming water and -O=C-CH-)...where as in a nucleophilic substitution reaction, two functional groups are switched.

    In the NAS textbook, look up the reaction between 2,4-dinitrophenylhydrazine and a carbonyl compound - that'll show ya exactly what happens in addition/elmination

    Having said that, im not sure if the formation of polyamides would count as addition/elimination too - instead of water, its HCl which is eliminated - blah!
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    An elimination reaction is one where a small molecule is emiminated. So yup, formation of polyamides would be an elimination cos a small molecule (HCl) is eliminated.. It's not only water..
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    safe guys just wanted to make sure. easy kris its all good man wat bout u? bet u cained that exam on wed init lol man i got bare work to do so ima get busy but if i need ne more help ur 1st on ma list lol for bio and chem safe :cool:
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    can someone answer this plz

    in hoffmann degredation amide to amine
    is there a reduction in number or carbons.

    e.g if propanamide added to naoh and bromine do you get propylamine or ethlyamine

    thanks in advance
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    safe...yes in hoffmann degredation amide to amine...there is a reduction in number of carbons
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    (Original post by raam001584)
    can someone answer this plz

    in hoffmann degredation amide to amine
    is there a reduction in number or carbons.

    e.g if propanamide added to naoh and bromine do you get propylamine or ethlyamine

    thanks in advance
    The general reaction is this, where R = alkyl group

    RCONH2 + 4NaOH + Br2 -------------> RNH2 + 2NaBr + Na2Co3 + H20

    so yup, you reduce the carbon chain by one which is why it's so useful in organic synthesis.
 
 
 
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