Literature support for carbanions?

User cd46b9a398

08-05-2015 19:30:12



For this molecule, C=C(C)C(=O)OCC[N+](=O)[O-] 2571991, JChem/CXCALC 15.5.4 deprotonates the methylene carbon alpha to the nitro group around pH 7.2 (see attached).  I would be interested to know what data you used to parameterize this. Do you have a reference please? 

User cd46b9a398

12-05-2015 02:53:26

I'm sorry to seem impatient, and perhaps you feel we should just ignore nitros, but some drugs have nitros, e.g. NITHIAMIDE and SIVIFENE and this is thus a serious problem for us. No way these should be carbanions.  Can you please check and let us know?


User 851ac690a0

13-05-2015 22:38:47


Thanks for reporting this pKa bug.

Sorry for the week long lack of answer but  unfortunately I received your question only today due to some technical issue.

Based on your feedback an improved version will be released asap, probably on the next week.

The pKa value of a "similar"  molecule and its experimental pKa value is given on the attached figure.

The carbanion species will be present in circa 7% at pH=7.2 according to the predicted pKa value of the molecule you brought  up in this discussion.

 Hoping  we were able to help you.