2-(1H-Imidazol-2-yl)-2,3-dihydro-1H-perimidine
Round 1
Reviewer 1 Report
In this manuscript, the authors reported the synthesis of 2-(1H-imidazol-2-yl)-2,3-dihydro-1H-perimidine as well as its characterization by NMR, XRD, and DSC. The authors need to address some concerns before it is considered for publication.
1. The desolvation of MeOH is clearly shown in the DSC data. The authors could add TGA analysis to obtain the weight loss and compare it with the weight percent of MeOH in the solvate (theoretical weight loss).
2. Did the authors try any heating experiment to see if a crystal form without MeOH could be obtained? Basically, the sample can be heated to 96 ºC and then check the PXRD pattern. I am curious if the material could keep crystallinity after MeOH molecule is removed.
3. Was the DSC data collected by modulated DSC?
Author Response
To the Editor of
Molbank
Sofia, February 10, 2023
Dear Prof. Huang,
Thank you very much for the time you and the other associate Editors have devoted to handle this submission. We are very grateful to you and Reviewers for the help permitting us to improve significantly the manuscript quality.
All corrections in the manuscript, inserted according to the Reviewer’s recommendations, are inserted as Track Changes.
The answers to the Reviewer’s recommendations are listed bellow:
Reviewer 1
In this manuscript, the authors reported the synthesis of 2-(1H-imidazol-2-yl)-2,3-dihydro-1H-perimidine as well as its characterization by NMR, XRD, and DSC. The authors need to address some concerns before it is considered for publication.
- The desolvation of MeOH is clearly shown in the DSC data. The authors could add TGA analysis to obtain the weight loss and compare it with the weight percent of MeOH in the solvate (theoretical weight loss).
The TGA is now inserted as Figure 2b and the figure captions are replaced by “Thermal analysis of the title compound (a) DSC thermogram of the title compound disclosing two endothermic effects associated with the release of methanol (60-110 °C) and (b) TGA data reveling a weight loss of ~13% corresponding to methanol molecule.”. “Thermogravimetric data visualizing the mass losses observed during heating of the title compound are shown on Figure 2b. The registered weight loss up to 110 °C is ~13wt% and correlates with the theoretical estimations for methanol release (12%). After 180 °C the TG registers the losses associated to the melting and evaporation of the title compound.” is added in the text. The equipment used and conditions are also inserted in the General part of the Experimental section.
- Did the authors try any heating experiment to see if a crystal form without MeOH could be obtained? Basically, the sample can be heated to 96 ºC and then check the PXRD pattern. I am curious if the material could keep crystallinity after MeOH molecule is removed.
No, we have not performed in situ PXRD diffraction.
- Was the DSC data collected by modulated DSC?
No, DSC data are not collected in MDSC mode.
Additional:
- The date of XRD deposition is corrected.
- Some additional information we found interesting is also inserted, which is as follows:
2.1. An additional keyword “methanol solvate”.
2.2. The text “Finally, a brief comparison between the product and its dehydrogenated analogue, 2-(1H-imidazol-2-yl)-1H-perimidine [32], both compounds being methanol insoluble, shows that the latter does not form similar solvate (Figure 5) despite the last purification step is trituration with methanol. This difference could be explained by a delocalization of the imidazolyl NH in the aromatic molecule, while in dihydroperimidine it is located on imidazolyl unit due to the absence of conjugation.”; lines 155-160 in the corrected document.
2.3. Figure 5, related with this text.
We hope these new insertions will be accepted. If that is out of the journal’s roles, we are open the remove.
Faithfully yours,
Prof. Dr. Vanya Kurteva
Author Response File: 
Author Response.pdf
