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    Does esters have a methylene group adjacent to a carbonyl group? (I'm not sure what it means neither, so could some1 please tell me what a methylene group is as well?)

    Also, does esters react with sodium solid? Does Halogenoalkanes react with sodium solid? (I think they do and form a halogen gas somehow but not really sure)... Thinking about it, it doesn't make sense if it reacts... I dunno...
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    You guyyyyyyys! Help me!, Wake up early u lazy buggers! Or just don't sleep like me! .
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    (Original post by MRLX69)
    Does esters have a methylene group adjacent to a carbonyl group? (I'm not sure what it means neither, so could some1 please tell me what a methylene group is as well?)

    Also, does esters react with sodium solid? Does Halogenoalkanes react with sodium solid? (I think they do and form a halogen gas somehow but not really sure)... Thinking about it, it doesn't make sense if it reacts... I dunno...
    Depends on the ester....

    A methylene group is a -CH2- group, so if your ester is CH3CH2COOCH3 for example then yes it does, but if your ester is CH3COOCH3 then it doesn't.

    Sodium reacts with esters (in the absence of hydrogen ions) to give a bimolecular addition product called an acyloin (an alpha-hydroxy ketone).

    Example:

    CH3COOCH3 gives CH3COCH(OH)CH3

    This reaction has been an important step in the synthesis of large ring compounds.

    Alkali metals such as sodium are strong bases and will liberate hydrogen from alcohols to give the alkoxy ion and this is used as evidence for the alcohol group.

    Sodium however will not release hydrogen from a halogenoalkane but it does readily form organosodium compounds (analogous to Grignard reagents) but these are often so reactive that they attack the starting halogeno compound or the solvent as soon as they are formed. Organolithium compounds do find some use in synthesis.

    Reactive metals such as sodium will also eliminate disubstituted halogenoalkanes to give an alkene.

    saludos
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    Wow... Thank you sooooo much for that. Ok, I'm stuck then.... I need to "Identify an unknown". I'm drawing a flow chart for it at the moment. And I need a simple test to seperate Primary Amines and Esters.

    I wanted to use the "Nitrous acid" test to get a positive test for the primary amine. But then I realised that it also give a positive test to a molecule with a methylene group adjacent to a carbonyl group.

    My second choice is to use "Acetyl Chloride" but it reacts with moisture present in the unknown.... Is Acetyl chloride my best bet? or should I risk it with nitrous acid and hope they don't realise that it reacts with some esters?

    I got my info from http://www.chemistry.ccsu.edu/glagov...sts/tests.html
    Have a look to see the tests and help me out . Thank you very much!
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    (Original post by MRLX69)
    Wow... Thank you sooooo much for that. Ok, I'm stuck then.... I need to "Identify an unknown". I'm drawing a flow chart for it at the moment. And I need a simple test to seperate Primary Amines and Esters.

    I wanted to use the "Nitrous acid" test to get a positive test for the primary amine. But then I realised that it also give a positive test to a molecule with a methylene group adjacent to a carbonyl group.

    My second choice is to use "Acetyl Chloride" but it reacts with moisture present in the unknown.... Is Acetyl chloride my best bet? or should I risk it with nitrous acid and hope they don't realise that it reacts with some esters?

    I got my info from http://www.chemistry.ccsu.edu/glagov...sts/tests.html
    Have a look to see the tests and help me out . Thank you very much!
    Why complicate your life so? Amines smell like fish esters don't!

    1º amines use HONO (NaNO2/HCl <5º) on warming bubbles of N2 appear
    2º amines yellowish nitrosoamines appear as an oil on the surface
    3º amines most books say no reaction (stick to this) - in fact its a very complex series of reactions in weakly acidic solution) producing a mixture of products

    You could also react them with ethanoyl chloride or ethanoic anhydride and crystallise and test the m.p. of the N substituted amide produced - this would be used for characterisation rather than testing the functional group.

    Which course would this be for?

    saludos

    charco
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    (Original post by charco)
    Why complicate your life so? Amines smell like fish esters don't!

    1º amines use HONO (NaNO2/HCl <5º) on warming bubbles of N2 appear
    2º amines yellowish nitrosoamines appear as an oil on the surface
    3º amines most books say no reaction (stick to this) - in fact its a very complex series of reactions in weakly acidic solution) producing a mixture of products

    You could also react them with ethanoyl chloride or ethanoic anhydride and crystallise and test the m.p. of the N substituted amide produced - this would be used for characterisation rather than testing the functional group.

    Which course would this be for?

    saludos

    charco
    Man! ur a life saver! You're doing chemistry I presume? I'm just doing mere A levels at the moment and shamefully, I have to admit that chemistry is not my strongest subject. Maths and physics is more my thing. The course I'm doing is in an organic chemistry module.

    Ok, the tests in the flow chart has to be 'wet tests', which are easy, crude, tests which give only a yes or no answer. I'm not allowed to get the substance from one test and lets say, recrystalise it and react it again. So HONO, which is the test for 1º amines, it doesn't react with esters right?

    Can you do me a big favour and look over my flowchart for me? .

    It'll be quick I promise. I'll pm you. Thank you!!!!!
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    (Original post by MRLX69)
    Man! ur a life saver! You're doing chemistry I presume? I'm just doing mere A levels at the moment and shamefully, I have to admit that chemistry is not my strongest subject. Maths and physics is more my thing. The course I'm doing is in an organic chemistry module.

    Ok, the tests in the flow chart has to be 'wet tests', which are easy, crude, tests which give only a yes or no answer. I'm not allowed to get the substance from one test and lets say, recrystalise it and react it again. So HONO, which is the test for 1º amines, it doesn't react with esters right?

    Can you do me a big favour and look over my flowchart for me? .

    It'll be quick I promise. I'll pm you. Thank you!!!!!

    yeah I'll take a look - you gotta link?

    It may take a few hours 'cos 'me muero de sueño' but I'll be around tomorrow

    saludos
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    (Original post by charco)
    yeah I'll take a look - you gotta link?

    It may take a few hours 'cos 'me muero de sueño' but I'll be around tomorrow

    saludos
    I've sent you a pm. Erm... I have it on a microsoft word document. I can send it to you via e-mail. if you give me ur e-mail via pm, i'd be very grateful. not that i'm not for all you've done for me already!
 
 
 

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