Methyl-3-(3-hydroxy-3-(4-(piperidin-1-yl)phenyl)-prop-2-enoyl)benzoate

Round 1

Reviewer 1 Report

The manuscript "Methyl-3-(3-hydroxy-3-(4-(piperidin-1-yl)phenyl)-prop-2-
enoyl)benzoate" describes the synthesis of the title compound using an asymmetric Claisen condensation. The structure of the resulting beta-diketone has been confirmed by 1H NMR, 13C NMR and X-ray crystallography. As expected, the enol tautomer is far more common than the diketone one and the authors convincingly prove this using both NMR and Xray data.

Comments:
- The asymmetric Claisen reaction proceeds with a low yield and produces a side product. The structure of the side product should be depicted in the manuscript.

- Experimental section, synthesis: Why is the 1H-NMR spectrum atom-mapped, but not the 13C-NMR?

- Since the authors synthesized a dye, UV/Vis and fluorescence spectra of the compounds would be interesting, if possible.

Author Response

Dear colleagues,

Thank you very much for careful reading of the manuscript and for your comments. Our responses are presented below:

Reviewer 1

1. The asymmetric Claisen reaction proceeds with a low yield and produces a side product. The structure of the side product should be depicted in the manuscript.

Reply: The structure of the side product was added to the Supporting Information (Figure S5).

2. Comment: Experimental section, synthesis: Why is the 1H-NMR spectrum atom-mapped, but not the 13C-NMR?

Reply: Signals in the 13C NMR spectrum were also assigned.

3. Comment: Since the authors synthesized a dye, UV/Vis and fluorescence spectra of the compounds would be interesting, if possible.

Reply: The title compound is a building block for construction of a dye – light-absorbing metal complex. A UV-vis spectrum of the title compound was measured, and the data were added to the text and into the Supporting Information – Figure S8.