Novel benzhydrylamine derivatives represented by general formulas (I) and (II) are useful as reaction reagents for the solid-phase synthesis of polypeptide amides making use of 9-fluorenylmethyloxycarbonyl group ("Fmoc"). An intermediate for these derivatives represented by the general formula (III) is also disclosed: ##STR1## where R.sub.1 and R.sub.2 each independently represents a C.sub.1-3 lower alkyl; n is an integer of 1-4; l is 1 or 2; and m is 1 or 2.