Review Reports

Round 1

Reviewer 1 Report

In the manuscript Verbitskiyt et al report the synthesis and structural characterization of (E)-2-(6-(4'-(diphenylamino)-[1,1'-biphenyl]-2-yl)-[1,2,5]oxadiazolo[3,4-b]pyrazin-5(4H)-ylidene)-2-(6-(4'-(diphenylamino)-[1,1'-biphenyl]-2-yl)-[1,2,5]oxadiazolo[3,4-b]pyrazin-5-yl)acetonitrile. The introduction and abstract of the manuscript clearly inform the reader about the topic of the work. I'm inclined to accept this manuscript however, a problematic aspect retgarding this manuscript that must be addressed. This is discussed below.

In the Results and Discussions section, the authors describe the reaction as a double nucleophilic attack of 2-cyanoacetic acid on the C(6) molecule of 5-aryl-substituted [1,2,5]oxadiazolo[3,4-b]pyrazine. It is worth emphasizing, however, that two molecules of compound 1 are involved in the reaction. The most important problem, however, is the description of the synthesis of the target compound. The authors carry out reactions on a scale of 0.25 mmol, but being aware that two molecules of compound 1 take part in this reaction, they do not use its excess (say twice). So my question is about the justification for using such a molar ratio. Do the Authors observe other products performing the reaction in this ratio? Is the reaction yield (57%) realistic to achieve?

Author Response

Reviewer 1:

Comments and Suggestions for Authors

In the manuscript Verbitskiyt et al report the synthesis and structural characterization of (E)-2-(6-(4'-(diphenylamino)-[1,1'-biphenyl]-2-yl)-[1,2,5]oxadiazolo[3,4-b]pyrazin-5(4H)-ylidene)-2-(6-(4'-(diphenylamino)-[1,1'-biphenyl]-2-yl)-[1,2,5]oxadiazolo[3,4-b]pyrazin-5-yl)acetonitrile. The introduction and abstract of the manuscript clearly inform the reader about the topic of the work. I'm inclined to accept this manuscript however, a problematic aspect retgarding this manuscript that must be addressed. This is discussed below.

In the Results and Discussions section, the authors describe the reaction as a double nucleophilic attack of 2-cyanoacetic acid on the C(6) molecule of 5-aryl-substituted [1,2,5]oxadiazolo[3,4-b]pyrazine. It is worth emphasizing, however, that two molecules of compound 1 are involved in the reaction. The most important problem, however, is the description of the synthesis of the target compound.

We would like to thank the reviewer for his/her valuable comments.

Authors' Responses to Reviewer's Comments (Reviewer 1)

The authors carry out reactions on a scale of 0.25 mmol, but being aware that two molecules of compound 1 take part in this reaction, they do not use its excess (say twice). So my question is about the justification for using such a molar ratio. Do the

Answer:

Indeed, we used the ratio of initial reagents 1 (1 equiv.) and 2 (1 equiv.). We also tried to use other ratios of 2-cyanoacetic acid, however, in this case, the yields of target product 3 were significantly reduced. So far, we cannot give a reasonable explanation for this fact. This requires much more time for a more detailed analysis.

Do the Authors observe other products performing the reaction in this ratio?

Answer:

It was not possible to isolate other products besides the target product, since the rest of the reaction mixture was a complex multicomponent mixture.

Is the reaction yield (57%) realistic to achieve?

Answer:

Yield 57% for target compound 3 was calculated based on the fact that 0.125 mmol of product 3 is obtained from 0.25 mmol of starting compound 1.