dormouse (Member)
04-21-00 08:05
No 108501
      diazoethane addition to get diazoketone? -Cherrie Baby  Bookmark   

Author  Topic:   diazoethane addition to get diazoketone? 
Cherrie Baby
Member   posted 09-13-98 03:29 AM          
On page 904 of Vogel (3rd ed) he gives the reaction of:
benzoyl chloride + diazomethane --> diazoketone which is then oxidised with Ag2O to give phenylacetic acid.

PhCOCl + CH2N2 --> PhCO.CHN2 --> PhCH2CO2H

What would happen if diazoethane was used instead? Could we expect this to happen.

PhCOCl + MeCHN2 -> Ph.CO.CH(N2).Me

If so, could that diazoketone be of use? How? Reduce it to get amphet?

Ph.CO.CH(N2).Me --> Ph.CH2.CH(NH2).Me

Is diazoethane too dangerous to risk using?

Note: Vogel uses p-methoxy-benzoyl chloride instead but, surely, the principle applies.

Member   posted 09-15-98 08:55 AM          
Cherrie Baby,
Apparently diazomethane is "reasonably" useable in solution form (usually 1M in THF), but still requires much care. Actually, guy in my department "apparently" has diazomethane generator, wasn't sure if I heard right, but I'm sure I did, because we then had a discussion about it's problems with ground-glass joints.
Diazoethane probably can exist, whether it is available I don't know, will have to look for my copy of Sigma-Aldrich catalog. Intuition tells me that it probably should be more stable, but I can't be sure.
Will try to keep you posted.

Take care,


Cherrie Baby
Member   posted 09-16-98 05:06 PM          
I was chatting to an experienced chemist about a 2nd hand diazomethane generator (a glassware rig with those special non-ground joints). He said it wasn't worth getting because diazomethane was generated in situ nowadays. Unfortunately the conversation stopped there because I didn't want to reveal my ignorance - so I never did find out precisely how the in situ generation was done.