Barium 5-(tert-butyl)-2,3-dihydroxybenzenesulfonate

Round 1

Reviewer 1 Report

D. A. Lukyanov and L. G. Rubicheva report the synthesis and partial characterization of the 5-(t-butyl)-2,3-dihydroxybenzenesulfonate barium salt. Thus, despite the product is interesting due to its potential applications, I found that the manuscript is not suitable for publication in the Molbank journal (at least not in its present form) mainly because the structure elucidation of the titled compound is not conclusive.

Related comments:

1- H and C NMR, as well as HRMS specrums were provided, but they are not enough to confirm the presence of the barium atom. Maybe an elemental analysis (or other technique) would be useful behind this purpose and would complete the work.

2- With respect to the H NMR spectrum: i) there is a peak around 4.80 ppm, any impurity? ii) in the manuscript the authors mentioned a couple of doublets integrating each 1, but in the spectrum it can be seen a doublet integrating 2. iii) where are the peaks of the two hydroxy groups (catechol)? If they disappeared by any reason, then a discussion about that will benefit the manuscript. iv) is the titled salt soluble in CDCl3? Indeed, in the manuscript authors mentioned D2O was used as solvent, but the spectrum says CDCl3.

3- With respect to the C NMR spectrum: i) in the abstract of the manuscript, authors stated that their procedure towards the titled product is highly scalable (enabling direct industrial production). However, the C NMR spectrum seems to be acquired using a sample containing only a few milligrams (see the lack of thickness in the baseline). ii) after predicting a spectrum using Shoolery tables (and prediction software), there should be no peaks above 150 ppm (so what happens with the peak at 161 ppm?). iii) the peak at 148.8 is negligible. iv) similarly to the H NMR spectrum, D2O or CDCl3?

4- With respect to the HRMS spectrum: i) the main peak matches with the C10H13O5S formula (I have no doubts), but the titled compound (C20H26O10S2Ba) with M = 628 cannot be found in the spectrum. In the same context, many possible fragmentation species from the titled product are not in the spectrum.

Recommendation:

I would suggest publication if authors attend all these points and concerns.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Authors corrected most of recommendations, hence making their manuscript publishable in the Molbank. However, their response to my point #1 says that a XRS spectrum was acquired in order to confirm the presence of Ba atom in the titled product, but at least the revised version of the manuscript I've downloaded from the MDPI SUSY-Platform does not contain any info and discussion about that. Thus, before publication, I suggest to correct the manuscript accordingly, as well as to place the spectrum into electronic supplementary material along with the other (NMR and HRMS) spectrums.

Author Response

Dear Referee,

we have added the XRF spectra to the SI and briefly discuss it in the text.