[wlflover]

Fo rlab we need to list down the impurities that showed up on our HNMR. For part one we had 2-methyl-1,3-dioxolane-2- (beta- (alpha, alpha- di phenylethanol) then we prepared 4,4-diphenyl-3-butene-2-one. Looking at my H NMR i noticed a singlet at 5.2 which is the H proton on the oxygen had appeared on both my part II NMR and Part III NMR. Is it possible for this to be an anion floating around in the part III product? there was also the impurity of toulene on the NMR would it be possible for this to shift further upfield on part III? 

[Dan]

5.2 could be DCM.

Check these tables:

http://chem.chem.rochester.edu/~nvd/NMRSolventImpurities.pdf

[wlflover]

i don't understand where the Ch2Cl2 would come from because we used CDCl3 to dissolver the solid.

[sjb]

i don't understand where the CH₂Cl₂ would come from because we used CDCl₃ to dissolver the solid.

Well, without knowing your exact procedure, it's hard to be sure, but did you run the reaction in DCM?

[Dan]

Yeah, solvent impurities come from all the solvents you may have used in the reaction, work up and purification as well as cleaning glassware.

[AC Prabakar]

Thank you Dan for your NMR impurity table!!!!
It is very helpful or me.