phagocytes Posted May 15, 2007 Share Posted May 15, 2007 How do the conditions for nitration of methyl benzoate differ from those for the nitration of benzene? what is the mechanism nitration of methyl benzoate to form methyl 3-nitrobenzoate? Thanks. Link to comment Share on other sites More sharing options...
Invader_Gir Posted May 18, 2007 Share Posted May 18, 2007 I'm fairly sure that only a few reaction conditions need to be modified. Methyl Benzoate consists of a benzene ring with an electron withdrawing carbonyl group attached. This being the case, an elevated temperature and a higher concentration of the electrophile should work. Substitution would also occur primarily meta to the carbonyl group. If multiple nitrations are required, an even higher temperature and concentration would be needed, since there is an electron withdrawing nitro group present on the ring aswell. Again that substitution would occur meta to both the carboxyl group and the existing nitro group. Hope this helps. Link to comment Share on other sites More sharing options...
phagocytes Posted May 18, 2007 Author Share Posted May 18, 2007 Thanks a lot! Link to comment Share on other sites More sharing options...
ecoli Posted May 18, 2007 Share Posted May 18, 2007 I'm fairly sure that only a few reaction conditions need to be modified. Methyl Benzoate consists of a benzene ring with an electron withdrawing carbonyl group attached. NO NO NO! Methyl Benzoate is a benzene ring with a carboxylic acid group attached. http://en.wikipedia.org/wiki/Methyl_benzoate And thus, you have to consider the withdrawing affects when nitrating. http://www.mhhe.com/physsci/chemistry/carey/student/olc/graphics/carey04oc/ref/ch12substituenteffects.html Since the COOH group is meta directing, there is only one carbon in which the NO2 group will be added. the mechanism will look like this: Link to comment Share on other sites More sharing options...
Invader_Gir Posted May 18, 2007 Share Posted May 18, 2007 No need to get snippy. It isn't a carboxylic acid group either. It's an ester, that is why I said carbonyl, similar but not the same. I did take into account the electron withdrawing effects. Also, there are two equivalent meta positions, and once the first nitro group is attached, nitration may happen again at the second meta position, ie, carbon 5. Link to comment Share on other sites More sharing options...
ecoli Posted May 18, 2007 Share Posted May 18, 2007 No need to get snippy. I didn't mean to sound snippy. lol. It isn't a carboxylic acid group either. It's an ester, that is why I said carbonyl, similar but not the same. stupid me... that's what I meant to say. I did take into account the electron withdrawing effects. Also, there are two equivalent meta positions, and once the first nitro group is attached, nitration may happen again at the second meta position, ie, carbon 5. hm... that's true, but since the ester group is also deactivating, couldn't you stop the reaction before this took place? Link to comment Share on other sites More sharing options...
Invader_Gir Posted May 18, 2007 Share Posted May 18, 2007 No harm no foul. hm... that's true, but since the ester group is also deactivating, couldn't you stop the reaction before this took place? Oh yes. In order to get the second nitration, higher temps, longer reaction times, would be required. Link to comment Share on other sites More sharing options...
ecoli Posted May 18, 2007 Share Posted May 18, 2007 OK... we're on the same page now. Link to comment Share on other sites More sharing options...
phagocytes Posted May 20, 2007 Author Share Posted May 20, 2007 NO NO NO! Methyl Benzoate is a benzene ring with a carboxylic acid group attached. http://en.wikipedia.org/wiki/Methyl_benzoate And thus, you have to consider the withdrawing affects when nitrating. http://www.mhhe.com/physsci/chemistry/carey/student/olc/graphics/carey04oc/ref/ch12substituenteffects.html Since the COOH group is meta directing, there is only one carbon in which the NO2 group will be added. the mechanism will look like this: i see Thanks! Link to comment Share on other sites More sharing options...
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