The manuscript from Prof. Dr Xavier Bantreil and co-workers has all of the flair and rigour that you expect from this group. They report the formation and use of Ru bipy photoredox catalysts over two mechanochemical steps. The detail the preparation of some useful epoxy resin jars and the starting material synthesis is also prepared using mechanochemical conditions. On the whole I think the manscript is of interest to the readership of RSC Mechanochemistry and should be accepted following consideration of the minor points below by the authors:

The yellow ‘S’ atom is difficult to see on a screen.

What does ‘facilitated purification’ mean? It becomes clearer later with the amide – but I think this is lost on the reader in the contents graphic.

Table 1 – add footnote that WC is tungsten carbide.

Table 2 – add a hardline between the conditions and yields shown for the substrate scope of the complexes from this work and literature comparisons shown in the final column, just so that it is clearer to readers.

Edit ‘ Beves and coll.’

Figure 1 is interesting, but I think it could be clearer to the reader that in the scheme that both of these are NMRs of the reaction mixture following acidic washes, it says it in the caption and text but the figure itself. Of course the amide has been removed but also the amide pyridine where the structure of this is not given in the same way as the ester.

The general procedures do not mention a scale of the reaction that was conducted, just the stoichiometries. I think it would be useful to readers to mention the scales (for the general process), or at least the applicable range of scales in a 5 mL jar for this process.

Remove ‘.’ Just before ‘or in a reductive Cope rearrangement’.

There is an error with reference 60, the DOI does not find the paper.

Could add the following reference: For the synthesis of organic photo redox catalsts by ball-milling, specifically 4CzIPN and analogues J. Org. Chem. 2021, 86, 20, 14095–14101

The authors have fully addressed the points raised by the referees and the paper should be accepted.