Sciencemadness Discussion Board

MOED synthesis (Brooker's merocyanin)

vibbzlab - 21-5-2023 at 06:21

Recently I read this literature on synthesis of Brooker'S Merocyanin (l-methyl-4-[(oxocyclohexadienylidene)ethylidene]-l,4-
dihydropyridine ) by M. J. Minch and S. Sadia Shah from University of the Pacific
Stockton, California
The prep went smooth as a cake. I followed the exact same procedure as per the literature including the stoichiometry. I will post some images and video link to my prep here. I will also include the link to the literature here.

figure 1 and 2 : 1,4 dimethylpyridinium iodide
figure 3 and 4 : red precipitate mentioned in the literature just prior to MOED
figure 5 and 6 : MOED crystallizing out and MOED after drying
figure 7 : Solvatochromism demonstrated in various solvents

THE LINK TO SYNTHESIS DEMONSTRATION VIDEO : https://youtu.be/Bs0ffWv2YQA

LINK TO LITERATURE : https://pubs.acs.org/doi/abs/10.1021/ed054p709


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pantone159 - 23-5-2023 at 06:24

That is an interesting looking compound. Any chance that somebody could post the journal paper? I do not have any access to read it. There is probably a main paper and a supplement with most of the synthesis details.

mayko - 23-5-2023 at 06:45

Minch, M. J., & Shah, S. S. (1977). Merocyanin dye preparation for the introductory organic laboratory. Journal of Chemical Education, 54(11), 709. https://doi.org/10.1021/ed054p709

Attachment: Merocyanin dye preparation for the introductory organic laboratory.pdf (611kB)
This file has been downloaded 234 times


Boffis - 24-9-2023 at 04:05

@vibbzlab, how long did you reflux the initial reaction mixture? The paper by Minch et al says 24hrs but I am trying a modified reaction using 3,4-dihydroxybenzaldehyde and after 2 hrs the reaction mixture is almost solid!! The ppt is a beautiful deep crimson as in your photo's.