NEW MATERIAL:The indole derivative of formula I (R1 is lower alkyl or aralkyl; R2 is H or lower alkyl; X is two H atoms or O) and its salt.

EXAMPLE: 2-[N-Benzyl-N-(3-piperidinopropyl)aminomethyl]indole.

USE: Pharmaceuticals (when X is two H atoms) and its preparation intermediate (when X is 0). It has long-acting excellent central muscle relaxing activity.

PROCESS: A compound of formula I wherein X is 0 can be prepared by reacting the indole-2-carboxylic acid of formula II or its reactive derivative with the piperidinopropylamine derivative of formula III in the presence of a condensation agent or in an inert solvent in the presence of a base at 0°CW room temperature. The product can be converted to another compound of formula I wherein X is two H atoms, e.g. by reducing with a reducing agent such as lithium aluminum hydride in anhydrous ether.