is it other than CH3COOH + C2H5OH => CH3COOC2H5
propanoic acid and isoamyl alcohol to make isoamyl propanoate?
Yes. CH3COOH and C2H5OH makes ethyl acetate or ethyl ethanoate.
You want propanoic acid and isoamyl alcohol to make isoamyl propanoate. I gave that ethyl acetate example to show you how it was named and put together. That's how I figure which is the alcohol and which is the acid to use.