3-(4-Fluorophenyl)-1-(1-(4-fluorophenyl)-3,3,3-trifluoroprop-1-en-1-yl)-5-fluoro-1H-pyrazole
Round 1
Reviewer 1 Report
Krylov, Terent’ev and co-workers report the synthesis of an intermediate under photochemical conditions, which cyclizes into the described pyrazole in presence of a base. The final compound has not been described beforehand.
The authors report 1H, 13C and 19F NMR HR-MS and FT-IR. Given the presence of a heteronuclei as fluorine, I expect to observe coupling constants H NMR and 13C NMR. In addition, a dubious peak in 19F NMR (close to the signal at -111.89) and difficult to explain is present as well.
Therefore, the authors should:
1) provide a novel 19F NMR peak zooming into this area in order to elucidate whether there is an unknown peak, and in case yes explain its origin.
2) provide novel 13C NMR spectra with a higher background-to-noise ratio in order to be able and discern C-F coupling constants.
3) coupling constants in 1H NMR as well if present.
4) report the yield in mg as well and not only as a percentage.
Author Response
Response to Reviewer 1 Comments
Point 1: Provide a novel 19F NMR peak zooming into this area in order to elucidate whether there is an unknown peak, and in case yes explain its origin.
Point 2: Provide novel 13C NMR spectra with a higher background-to-noise ratio in order to be able and discern C-F coupling constants.
Point 3: Coupling constants in 1H NMR as well if present.
Response: At the request of the Reviewer and to ensure the structure of the obtained product, we provided high-quality 1H, 13C and 19F NMR spectra. The description of the spectra was also checked and rewritten accordingly.
Point 4: Report the yield in mg as well and not only as a percentage.
Response: In accordance with the Reviewer's requirement, we indicated the yield of the target product in milligrams as following: “The crude product was purified by column chromatography (hexane/dichloromethane, 1:1, v/v) to afford 77 mg (42%) of target compound (2) as a light-yellow oil…”.
Reviewer 2 Report
It is my pleasure to recommend this one-compound synthesis manuscript for publication. It describes unusual photo-induced trifluoromethylation/dimerization reactions leading to interesting fluoro pyrazole.
Minor improvement would include:
1) Abstract improvement - "The reaction proceeds..." it is yet not told what reaction.
2) Characterization - 13C NMR should indicate JC-F.
Author Response
Response to Reviewer 2 Comments
Point 1: Abstract improvement - "The reaction proceeds..." it is yet not told what reaction.
Response: At the request of the Reviewer we modified this sentence as follows: “In this work, the title compound was synthesized via the visible-light induced radical denitrogenative trifluoromethylation of the corresponding vinyl azide followed by Cs2CO3-mediated defluorinative cyclization of the resultant azine.”
Point 2: Characterization - 13C NMR should indicate JC-F.
Response: In accordance with the Reviewer's requirement, the description of the 13C NMR spectra was checked thoroughly and appropriately rewritten, indicating all observed C-F coupling constants.
Round 2
Reviewer 1 Report
The authors correctly addressed all previous comments. therefore, I agree that this one-compound paper shall be published in Molbank
