How to use isoamyl acetate

Consult your flavor company, for precise dose which can be in parts per million.
Its not something anyone could add according to personal whim.You need expert advice from. From flavor experts.
Also read the food chemical CODEX for reference in use of isoamyl acetate in food.

Having prepared such chemicals, i guess you have synthesized this yourself in the lab. And thus the query??
It is soluble in water and ethanol, and can be attempted.
You may also find this information: It is a substance permitted for direct addition to food for human consumption, as long as (a) it is used in the minimum quantity required to produce its intended effect.

Yup, probably you are right & thanks for the information regarding my queries.. Actually I am trying to synthetically blend NA category of beer in various flavor with all related acceptations..like bitterness/sourness/tingling sensation etc without any time taking traditional method like brewing & fermentation with yeast then again so many filteration process / alcohol discarding etc.etc
Can you suggest more?

You are making things complicated..You want synthetic beer well you can be masochistic in tiresome effort of combining flavor components until you got the right taste.
I doubt using even mixture design in design of experiments you can get your zero alcohol beer with the right taste ,body ,etc. If compared to the established process .
The standard means of non alcoholic beer is to remove the alcohol from fermented beer or to use special yeast and techniques to prevent alcohol formation
https://www.getgruvi.com/blogs/posts/how-is-non-alcoholic-beer-made