Bis(2,6-di(pyridin-2-yl)pyridin-4-yl)-6,6′-(1,2-diselanediyl)dihexanoate

Round 1

Reviewer 1 Report

Dear authors,

The manuscript needs improvement. In the attached PDF file, I highlighted primarily the language errors. Additionally, the experimental part requires improvement. Both procedures are written in different styles. First, write this fragment following the descriptions used in this journal. The spectroscopic characteristics of the obtained diselenides lack 77Se NMR spectra, which is currently the standard in describing organoselenium compounds. Please note the following publications: Tetrahedron 1996, 52, 11163–11176; Tetrahedron Letters 2005, 46, 3331–3334.

Comments for author File: Comments.pdf

Please improve your English according to the comments in the highlighted text sections.

Author Response

Manuscript ID: molbank-2769161

Type of manuscript: Short Note

Title: Bis(2,6-di(pyridin-2-yl)pyridin-4-yl)-6,6'-(1,2-diselanediyl)dihexanoate

Authors: Evelyn Popa, Adelina A. Andelescu*, Valentin Badea, Paula Svera (m. Ianăşi), Elisabeta I. Szerb

We are very grateful to the reviewer for his time and evaluation of our manuscript. We have addressed all the points raised, and we hope that our answers will be fully satisfying.

In reply we added the followings:

The manuscript needs improvement. In the attached PDF file, I highlighted primarily the language errors.

Response: We thank the referee for the improvements. We corrected all his suggestions in the main article.

Additionally, the experimental part requires improvement. Both procedures are written in different styles. First, write this fragment following the descriptions used in this journal.

Response: We thank the referee for the pertinent observations. We corrected the experimental part.

The experimental procedure for compound 2 was re-written in a style similar to compound 1.

The spectroscopic characteristics of the obtained diselenides lack ⁷⁷Se NMR spectra, which is currently the standard in describing organoselenium compounds. Please note the following publications: Tetrahedron 1996, 52, 11163–11176; Tetrahedron Letters 2005, 46, 3331–3334.

Response: The referee is correct, the simplest way to characterize organoselenium compounds is to do ⁷⁷Se NMR spectra. However, we do not have the possibility to perform this investigation, and the final characterization was done by using complementary investigations 1D and 2D NMR spectroscopy, FT-IR, elemental analysis) as in the new inserted references: ¹H NMR and MALDI-TOF mass spectrometry: 20 [Han W., Zhang S., Qian J., Zhang J., Wang X., Xie Z., Xu B., Han Y., Tian W. Redox Responsive Fluorescent nanoparticles based on Diselenide-containing AIEgens for Cell imaging and Selective Cancer Therapy. Chem. Asian J. 2019, 14(10), 1745-1753], ¹H NMR and ¹³C NMR spectra, mass spectra (MS), elemental analysis 21 [Frizon T. E., Rafique J., Saba S., Bechtold I. H., Gallardo H., Braga A. L. Synthesis of Functionalized Organoselenium Materials: Selenides and Diselenides Containing Cholesterol. EurJOC 2015, 16, 3470-3476], and the references 12: ¹H NMR and ¹³C NMR spectra, mass spectra (MS), elemental analysis [Nie Y., Zhong M., Li S., Li X., Zhang Y., Zhang Y., He X. Synthesis and potential anti-cancer activity of some novel selenocyanates and diselenides. Chem. Biodivers. 2020, 17(5), e1900603] and 19 (Zhang W., Lin W., Pei Q., Hu X., Xie Z., Jing X. Redox-Hypersensitive Organic Nanoparticles for Selective Treatment of Cancer Cells. Chem. Mater. 2016, 28, 4440−4446). Moreover, in this latter reference (19) the ¹H NMR and ESI MS spectra of compound 1 are published, our NMR results being identical. For both compounds (1 and 2) were performed additional 1D and 2D NMR spectroscopy that permitted the assignment of the peaks of the methylene groups neighboring the carboxyl/ester and diselenide groups, while the elemental analysis support fully the structure and high purity of the compound.

An additional confirmation arises from the shift of the methylene protons neighboring the carboxyl group in compound 1 (H^E) from 2.31 ppm to 2.54 ppm in the tpy derivative (compound 2) further supported by ¹³C-NMR as described in the article.

New bibliography was added to support the complementary analysis performed [20, 21].

Round 2

Reviewer 1 Report

Please correct the following issues:

Line 53 – add space – firstusing

Line 141 – correct the name of compound - 2,6-Di(pyridine-2-yl)pyridine-4-ol

Line 153 – remove space between first and on

Line 171 – add space - 0.202 g,2.56

Line 172 – remove space - (5 mL) ,

Line 173 – remove of and change were to was - (5 mL) of were

Line 177 – remove coma - After, the

Line 191 – remove space - mmol) , 2

Line 191 – add comma and space after g - (0.129 g0.52

Line 192 – add were before dissolved - ) dissolved

Line 196 – before dissolved add – “the residue was”

Line 196 - CHCl3, washed – remove comma and add “and”

Line 197 - (3x50 mL), the organic – change comma to dot and start new sentence: The organic

Line 198 – change taken with to dissolved in

Line 199 – add off after filtered

Line 200 – change taken to evaporated

Line 205 – add space and period after bracket - mmol,18.8 %)

Line 206 – add period after bracket - and nC=C)

Thank you for your answers regarding the characteristics of the compounds obtained and the inability to perform a 77Se NMR spectrum.

I posted the comments about English above, along with the other comments.

Author Response

We are very grateful to the reviewer for his time and evaluation of our manuscript.  

We corrected all his suggestions in the main article.

Kind regards