Author Topic: Lower limit of boro  (Read 1065 times)

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Argox

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Lower limit of boro
« on: March 07, 2002, 10:58:00 AM »
Theoretical lower limit of NaBH4 to PMK in red./amin. is 0.25 mol NaBH4 for every mol PMK.  What is the practical lower limit?  0.47 moles works great (per LaBTop writeup), how about 0.38 moles?

Edit:  Was I clear?  How little borohydride can be added per mol of MDP2P (=PMK=ketone) before yield suffers?  Anybody go as low as 0.38?

Argox

  • Guest
Re: Lower limit of boro
« Reply #1 on: March 07, 2002, 02:36:00 PM »
I feel like a pariah.  Oh, rejection, how bitter.  Have I fucked up that much, guys? 

In the reduction amination of MDP2P with NaBH4, where 0.25mol borohydride is the theoretical lower limit (I assume it donates all four H+) and LaBTop's write-up using 0.47 mol NaBH4 per mol of ketone works like a charm, what would be the lower limit before yields suffer?  All just theoretical information, of course.  Will the use of 0.38 mol boro per mol of ketone suffer reduced yield?  Anybody know?  I wouldn't want to have to experiment, the procedure is not looked kindly upon by the local authorities.

Argox

  • Guest
Re: Lower limit of boro
« Reply #2 on: March 07, 2002, 05:09:00 PM »
Happy days!  I have heard from the angels on high, the burning bush spoke to me (PM actually).  The opinions have been weighed.  There is no general concensus, but the opinions are VERY learned and the opiners VERY esteemed.  Expect a SHORT write-up either way.

Regards
Argox