Question

I determined this as the product of my aldol reaction I performed with 4-methoxybenzaldehyde and 3'-methoxyacetophenone. It was approved by my supervisor so I am pretty confident it is correct.

Looking at the IR spectra, there is a large broad peak at ~3300, which I know usually indicates alcohol or acids. There is no alkyne or amine in the structure. What could account for this peak? Is it just a spectrometry fluke or am I just missing something... (I used perkinelmer vers. 10.5)

Thank you!!

Answer 1

This O-H is responsible for the broad peak at 3300cm-1. Он о NaOH 4-methoxybenzaldehyde 3'-methoxyacetophenone aldol addition product NaOH Heat When you use 4-methoxybenzaldehyde and 3'-methoxyacetophenone, they produce aldol addition product initially. After dehydration occurs to give the final compound. If the dehydration is not completed then the it will have some addiiton product. This product has O-H group which gives broad peak in IR at 3300 cm-1. Thus, in your case the conversion is incomplete.