Hi there,
I did an reaction (N-acylation of isatine with acetanhydride with no base) that is from organic syntheses (Organic Syntheses, Coll. Vol. 3, p.456 (1955); Vol. 28, p.70 (1948).) so it should work without any troubles.
Anyway I already perfomed this reaction in the past and everything was ok however today I run into a problem: I did an TLC which clearly showed that there is no starting material present and only product is in the reaction and did the workup (cool to RT, filter and wash with ether). The color of product was right (dark green, starting material was red) however the HPLC shows that there is basicaly only starting material and not my product. I have no idea what is going on since other analysis that are performed on that HPLC mashine are fine.
Any ideas?
btw heard that TLC is more sensitive that UV/VIS detectors in hplc systems, is that right?