Unexpected Formation of 4-[(1-Carbamoyl-3-oxo-1,3-dihydro-2-benzofuran-1-yl)amino]benzoic Acid from 4-[(3-Amino-1-oxo-1H-2-benzopyran-4-yl)amino]benzoic Acid

Round 1

Reviewer 1 Report

1) Please combine all supplemental information (SI) files into one file. 

2) Your NMR discussion would be more scientifically sound if you compared your NMR data to previously reported compounds with similar structures.

3)The authors should attempt to produce a crystal structure of compound 11a

4) Line 30 Phthalides shouldn't be capitalized

5) Line 46-49 Make sure to cite figure 2 in text

6) So technically you did not make compounds that look like 7 in figure 2. You should make it clearer to the reader that you're making precursors for this type of structure.

7) In the proposed mechanism for compound 11 (line 107) you suggest oxygen reacting with the double bond to form II. Have similar mechanisms been reported? If so, cite them.

8) Line 175 fix precipitate de product

9) Line 179 fix RMN

10) The abstract is excessively wordy. Consider rewriting.

11) You have a .mol file (I'm assuming a cystal structure) of one of these compounds in the supplemental however there is no mention of this in the text. 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The formation of the two new compounds needs to be proven by HRMS mass spectrometry or even elemental analysis. Assigning the 1H NMR and 13C NMR signals without the use of 2D NMR spectra 1H-13C HSQC, 1H-13C HMBC is a lottery. The 1H-15N HSQC and 1H-15N HMBC spectra could also be very useful. In the case of the proposed mechanism, I consider it is exaggerated to consider the formation of ethaneperoxoic acid intermediate in stage IV. If the structure of the synthesized compounds is also confirmed by mass spectrometry and 2D NMR spectroscopy, respectively, it is necessary to re-evaluate this mechanism. The correct IUPAC name for peroxyacetic acid is ethaneperoxoic acid.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript describes the novel synthetic method of carboxamide-phthalide derivatives via the unexpected ring rearrangement of diamino isocoumarin derivatives.

As mentioned by the authors, the products newly obtained could be converted to a variety of heterocycles. Furthermore, the mechanism proposed is reasonable and acceptable.

Chemistries described in this paper would be a nice piece of work and of interest for a number of researchers in this field.

I recommend this manuscript for publication in Molbank.

 

A minor points:

In the introduction part, although authors discuses about isocoumarin derivatives, a spiro-compound 7 was suddenly appeared as a target molecule.  I cannot understand the relationship between these two compounds.

Moreover, the initial target molecule 7 was not mentioned in the conclusion part, anymore.  I was little confused by this story.

I think if the relationships between these compounds describe clearly, the quality of the paper would be increased.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

All recommendations have been fulfilled. Good luck!