To obtain the subject compound to be based for synthesizing an amide- like compound useful for producing a small amount sample for biological screening by reacting a specific acetic acid product with an aminomethyl resin in the presence of a dehydrating agent.

This compound expressed by the formula I {[P] is a supporter; R1, R2 and R3 are each H, a 1-6C alkyl, etc.; R is F, Cl, etc.; (n) is 0-3; (m) is an amount of aldehyde} or formula II (e.g. a resin-bonded compound or an amide-like compound) is obtained by, e.g. in the formula I, reacting indol-3- carboxyaldehyde with a halogen acetate in a suitable solvent and in the presence of a base, then hydrolyzing the resultant product by a slightly caustic compound, thus generating 3-formyl-indol-1-yl-acetic acid. Next, the indole acetate product is reacted with a suspended aminomethyl resin in an inert solvent at a room temperature in the presence of a dehydrating agent (e.g. carbodiimide) for a sufficient time to produce the compound of the formula I.