3-Amino-4-(diphenylamino)-1H-2-benzopyran-1-one

Round 1

Reviewer 1 Report

In this manuscript, the authors have described the synthesis of a novel compound, 3-amino-4-(diphenylamino)-1H-2-benzopyran-1-one, by a two-step methodology. After carefully studying this work, this reviewer recommends the article can be published after major revisions:

·  references Saikia & Gogoi, Adv. Synth. Catal. 2018, 360 (11) 2063 and Ashraf, Chem. Heterocycl. Comp. 2016, 52, 149 must be included in general methodologies for isocoumarin synthesis (along with references 8-10);

·  replace “two steps” by two step” or “two-step”;

·  Figure 1 caption must be replaced by “Representative examples of isocoumarin derivatives with...”;

·  Lines 31-40: the sentence is too long, it should be divided into small sentences;

·  Line 36: in “multicomponent reactions” the first words must not be capitalized;

·  Line 39: in the sentence “and certainly, isocoumarins”, the word " certainly " doesn't seem appropriate, must be replaced;

·  Lines 39, 44, 79, etc.: numbers 9, 10, 12, etc. must not be in parentheses since are general names; numbers in parentheses should only be used when using the full name, e.g. 2-formylbenzoic acid (7);

·  Lines 43-45: rewrite the sentence, or insert a dot after [14];

·  Line 54: a paragraph cannot start with “therefore”, this is an adverb used to o show the cause and effect relationship between two statements; it must be removed or the previous paragraph and this must be joined;

·  Line 56 and 63: include compound numbers, 16 and 17, after the name of compounds (without parentheses);

·  Scheme 3: assign references to each of the conditions indicating them in the scheme;

·  Line 72: “One last experimental observation is…” it looks weird; rewrite the sentence;

·  Schemes 7 and 8: replace “r.t” by “rt” or “r.t.”;

·  Line 78: include reference 14 after the Opatz and Ferenc methodology;

·  Line 81: “in the nitrogen atom at the C-4 position” must be “at the position 4” or “at C-4 (without position)”;

·  Line 84: are not compounds derived from the isocoumarin nucleus, they are compounds containing the isocoumarin nucleus;

·  Scheme 7: compound 19 was synthesized without TMSCN? What was the yield? It must be included in scheme;

·  Scheme 7: remove R1 from structures, since it is H;

·  Line 94: the authors assume that compound 21 was in the reaction mixture. Was there any NMR evidence of reaction crude? If not, scheme 8b and “results” in lines 96-99 must be removed;

·  Scheme 8a: compound 20 must be renumbered to, for instance 20a, since is a particular case of 20 (cf. scheme 6);

·  Line 106: Moreno-Fuquen synthesize compound 24 in solvent free conditions, therefore, it should be mentioned that it was an adaptation of the methodology and not the methodology reported by these authors;

·  Scheme 9: The yield of compound 24 must be included in scheme; the overall yield of the two-step protocol must be given;

·  Line 131 and so on: the numbering of atoms in structure 24 should be placed to make it easier to read;

·  Section 4.2: 1H, 13C NMR and ATP experiments are not enough to make the complete assignment of all signals in proton and carbon spectra, additional experiments such as 2D NMR are needed; therefore, assignments that are only presumption or based on simulation should be removed; the same applies for results section (lines 131-144);

·  Section 4.2: elemental analysis or HRMS must be furnished for compound 24;

·  Ref. 1: missing volume and issue; page numbers are wrong;

·  Ref. 2 to 15: without issue number and Ref. 16-19, 26, etc: with issue number; the format must be uniform;

·  References 1, 3, 5, 7, 12: missing italics (e.g. Penicillium, Setosphaeria Rostrate…)

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

This reviewer recommends the article can be published after minor revisions:

Fig.1 caption: replace "isocoumarins derivatives" by "isocoumarin derivatives";

Line 79: replace "product 19 and 21" by "products 19 and 21";

Scheme 9: include MeOH under the second arrow (with "reflux");

Lines 119-124: identify scheme 10 in this paragraph (maybe after the 1st sentence);

Line 197: the theoretical mass calculated for [M+H]+ (C21H17N2O2) is wrong, otherwise the accuracy is ~740 ppm (an acceptable value of the measured mass should be within 5 ppm of the accurate mass (Gross, M. L. (1994). Accurate masses for structure confirmation. Journal of the American Society for Mass Spectrometry, 5(2), 57.); the correct calculated value should be 329.12900, which corresponds to an accuracy of 0.8 ppm. Please check the values.

Author Response

Plese see the attachment

Author Response File: Author Response.pdf