A compound which is produced in the course of a chemical synthesis, which is not itself the final product, but is used in further reactions which produce the final product; also called synthetic intermediate, intermediate compound or intermediate product; -- contrasted to starting material and end product or final product. There may be many different intermediates between the starting material and end product in the course of a complex synthesis; as, many industrial chemicals are produced primarily to be used as intermediates in other syntheses.

A chemical intermediate is any substance generated by one step in a synthetic process and used for the succeeding step.

reactive intermediate; reaction intermediate. A highly reactive substance that forms and then reacts further during the conversion of reactants to products in a chemical reaction. Intermediates never appear as products in the chemical equation for a net chemical reaction.

product of a reaction that immediately becomes a reactant of another reaction.

a substance formed during a chemical process before the desired product is obtained

An intermediate in a reaction can be isolated. It is a species that is in a local energy minimum, i.e. it needs to be further activated to form the end products. It is not the same as a transition state.

A material produced during steps of the synthesis of a drug substance that must undergo further molecular change before it becomes the drug substance