N-4-phenyl picolinamide – Feb 10-Feb18 update


TLC of KG04 together with reagents, phenylisocyanate, picolini acid, and diisopropylethylamine in ethylacetate/hexane eluent.

(Left, TLC in 1:9 ratio, center 2:3 ratio, right 2:3 ratio with components diluted)

The product KG04 was dissolved in acetone (not the one from the wash bottle), and TLC of of it was taken together with phenylisocyanate, picolini acid, and diisopropylethylamine in ethylacetate/hexane as eluent in the ratio of 1:9 (1.0mL ethylacetate and 9.0mL hexane). As seen in the picture (left), not much movement of the molecules were observed. Hence, new eluent for TLC was prepared with ethylacetate:hexane ratio of 1:2 (5mL and 10mL respectively). As seen in the middle of the picture, the result was better, but still not clear distinction, so another TLC was run will similar eluent, but this time the samples with diluted with acetone. The right TLC plate in the picture shows the result.

It is clear that the product does contain some picolinic acid and phenylisocyanate, but another method to analyse the product is required for detailed understanding.

Chemical dip method was done on the TLC plate, but no new spots were formed.


One thought on “N-4-phenyl picolinamide – Feb 10-Feb18 update

  1. From the TLC, it doesn’t look like there’s any product in this mixture. At this point, I’d suggest starting the prep from the beginning one more time. Double check the amounts of each reagent and try following the literature prep exactly. The “11mg” yield they report is less than we need to move on to our next step, but if we can get an exact repeat of the lit prep to work, then we can try scaling up a bit.

    Trying to follow: “Facile Amide Bond Formation from Carboxylic Acids and Isocyanates”
    Org. Lett., 2011, 13 (9), pp 2256–2259 http://pubs.acs.org/doi/abs/10.1021/ol200531k
    The word “facile” in the title was too tempting…

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