Hi, I am a student who just begin work with organic synthesis. Lately, I did a lithiation reaction following by carboxylation with 4-methyl thiazole thiazole using nBuLi for lithilation, next added CO2 to make 4-methylthiazole 2-carboxylic acid. After finishing rnx, I added diluted HCl to adjust pH to ~5 and separated organic layer. However, TLC analysis supposed that the lowest spot (which I think that it is my product) presented only in the aqueous phase. I even tried to reduce pH to ~2 but still could not obtain product in organic phase. How can I separate my product? I'm really appreciated any kind of help.