PURPOSE: To carry out the deprotection of an amino group protected with 2- alkenyloxycarbonyl group, without producing hardly separable by-products, in high efficiency, by using a platinum-group metal compound catalyst in the presence of formic acid or its salt.

CONSTITUTION: A protected amino compound having amino group protected with 2-alkenyloxycarbonyl group is made to contact with a platinum-group metal compound catalyst, especially a 0-valent olefin complex or bivalent organic compound of preferably palladium, in the presence of formic acid or its salt, especially formic acid, ammonium formate or formic acid lower amine salt. The protective group can be eliminated by this process to give an amino compound devoid of the above protective group, with simple operation, in high efficiency, without producing hardly separable by-products. The obtained compound is useful as pharmaceuticals, agricultural chemicals, industrial chemicals or their intermediates, etc. Since the process is carried out under mild reaction condition, it can be applied to an optically active amino acid without causing racemization.