4,7-Bis(2,3,3a,8b-tetrahydrocyclopenta[b]indol-4(1H)-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine
Round 1
Reviewer 1 Report
The article entitled '4,7-Bis (2,3,3a,8b-tetrahydrocyclopenta [b] indol-4 (1H) -yl) - [1,2,5] thiadiazolo [3,4-c] pyridine' describes the synthesis of a new donor-acceptor-donor (D-A-D) type molecule in a two-step procedure that includes aromatic nucleophilic substitution and Buchwald-Hartwig cross-coupling starting form compounds 2 (requiring two-step synthesis from commercially available precursor) and 3 (no provided details on synthesis or availability). Since the aromatic nucleophilic substitution stops at single bromine substitution by amine 3 resulting in the formation of intermediate product 4, the additional step of Buchwald-Hartwig cross-coupling was needed. Are the Authors considering the direct introduction of the Buchwald-Hartwig cross-coupling procedure to substrate 2 with two equivalents of 3 to omit the formation of intermediate 4? There is no comment about such an opportunity, but it seems to be a logical simplification of the performed synthesis.
New compounds 4 and 1 (not reported in Reaxys or SciFinder) are fully characterized by 1H NMR, 13C NMR, IR spectroscopy, melting point measurement, MS, HRMS and elemental analysis. The data provided in the SI part are in agreement with the experimental part.
The language of the manuscript is appropriate and correct; however, several editorial errors and issues requiring clarification are listed below:
- Line 44 - 'monoamine derivative-aqueous 4' What does aqueous derivative mean? The reaction was performed in DCM or MeCN without water addition.
- Line 45 – “The reaction in acetonitrile proceeded much faster than in a less polar dichloromethane.” The Authors should provide some details like yield or reaction time for comparison.
- Scheme 1 – compound 5 should be somehow separated from 1 and supported with reference since, in the current form, it is quite confusing to the reader – it looks like 5 is a second product of the reaction.
- Line 93 - Remove one dot
- Synthetic procedures of 1 and 4 - 'cm-1' should be taken into brackets in the same manner as 'ppm'.
- The SI part – please reduce the number of marked picks in the compound 4 IR spectra.
- Please add the information about the 3 origins: is it commercially available or prepared?
- Reference part – please check the style of all references carefully; quite often spaces between first names letters or numbers are omitted (ref. 2, 4, 6, 7, 8, 10, 11, 12, 13). Choose the appropriate type of page separator '-' or '–'. Remove hyperlinks from DOI or add hyperlinks to all cited articles.
In summary, the manuscript can be published in the Molbank Journal after minor revisions.
Author Response
Reviewer 1
The authors are grateful to the reviewer for a kind and highly professional review.
Point 1.
Are the Authors considering the direct introduction of the Buchwald-Hartwig cross-coupling procedure to substrate 2 with two equivalents of 3 to omit the formation of intermediate 4?
Response from authors.
The following phrase has been added to the text of the paper: “We have shown that the reaction of compound 2 with amine 3 (3 equiv) under the conditions of the Buchwald-Hartwig reaction leaded to complete decomposition of the starting product; it was not possible to isolate individual products from the reaction mixture.”
Point 2.
Line 44 - 'monoamine derivative-aqueous 4' What does aqueous derivative mean? The reaction was performed in DCM or MeCN without water addition.
Response from authors.
The word " aqueous" has been removed from the text of the paper.
Point 3.
“The reaction in acetonitrile proceeded much faster than in a less polar dichloromethane.” The Authors should provide some details like yield or reaction time for comparison.
Response from authors.
The required data has been added to the text of the paper.
Point 4.
Scheme 1 – compound 5 should be somehow separated from 1 and supported with reference since, in the current form, it is quite confusing to the reader – it looks like 5 is a second product of the reaction.
Response from authors.
Scheme 1 was corrected as suggested by the reviewer.
Point 5.
Line 93 - Remove one dot
Response from authors.
Corrected as suggested by the reviewer.
Point 6.
Synthetic procedures of 1 and 4 - 'cm-1' should be taken into brackets in the same manner as 'ppm'.
Response from authors.
Corrected as suggested by the reviewer.
Point 7.
The SI part – please reduce the number of marked picks in the compound 4 IR spectra.
Response from authors.
Corrected as suggested by the reviewer.
Point 8.
Please add the information about the 3 origins: is it commercially available or prepared?
Response from authors.
The required information added.
Point 9.
Reference part – please check the style of all references carefully; quite often spaces between first names letters or numbers are omitted (ref. 2, 4, 6, 7, 8, 10, 11, 12, 13). Choose the appropriate type of page separator '-' or '–'. Remove hyperlinks from DOI or add hyperlinks to all cited articles.
Response from authors.
Corrected as suggested by the reviewer.
