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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Ayushmaan on October 31, 2017, 02:22:58 PM

Title: Reaction mechanism
Post by: Ayushmaan on October 31, 2017, 02:22:58 PM
What's the reaction mechanism when formaldehyde reacts with hydroxylamine??
Title: Re: Reaction mechanism
Post by: Borek on October 31, 2017, 02:59:41 PM
Please read the forum rules (http://www.chemicalforums.com/index.php?topic=65859.0). You have to show your attempts at answering the question to receive help.
Title: Re: Reaction mechanism
Post by: Ayushmaan on November 01, 2017, 10:55:50 AM
Alright, now can you please help me Figure out the mechanism???
Title: Re: Reaction mechanism
Post by: rolnor on November 01, 2017, 11:03:04 AM
Can you say which one is electrophile and nucleophile Ayushmaan?
Title: Re: Reaction mechanism
Post by: Ayushmaan on November 01, 2017, 11:09:44 AM
I predicted the mechanism like this.

Lone pair on in formaldehyde double bond with oxygen is rearranged as lone pair shifts on oxygen and oxygen acquires negative charge.
Then the nitrogen on H3NO attacks the positively charged carbon of formaldehyde.
This is how i attempted it.

If it's incorrect please let me know what's the correct one.
Title: Re: Reaction mechanism
Post by: Ayushmaan on November 01, 2017, 11:12:23 AM
Well i am not sure rolnor but i do know that final product is oxime :P
Title: Re: Reaction mechanism
Post by: Babcock_Hall on November 01, 2017, 11:22:28 AM
I predicted the mechanism like this.

Lone pair on in formaldehyde double bond with oxygen is rearranged as lone pair shifts on oxygen and oxygen acquires negative charge.
Then the nitrogen on H3NO attacks the positively charged carbon of formaldehyde.
This is how i attempted it.

If it's incorrect please let me know what's the correct one.
What about a concerted attack on C=O, by the lone pair on N?  If your final product is an oxime, how will you encourage the oxygen atom from formaldehyde to leave? 
Title: Re: Reaction mechanism
Post by: Ayushmaan on November 01, 2017, 11:34:16 AM
I agree with you babcock_hall
So what should be the final mechanism?
Title: Re: Reaction mechanism
Post by: Babcock_Hall on November 01, 2017, 05:32:31 PM
You are required by the forum rules to show your attempt before we can help you.  I think that the next step might involve proton transfer.  Try drawing as much of the mechanism as you can.
Title: Re: Reaction mechanism
Post by: Ayushmaan on November 02, 2017, 11:47:00 AM
I tried but it im still confused about the last step
Title: Re: Reaction mechanism
Post by: Babcock_Hall on November 02, 2017, 11:59:06 AM
Please show what you have, and we can help you from there.
Title: Re: Reaction mechanism
Post by: Ayushmaan on November 04, 2017, 11:47:46 PM
I figured it out
Title: Re: Reaction mechanism
Post by: Ayushmaan on November 04, 2017, 11:48:20 PM
Never mind