A method for production of 4-boronophenylalanine from 4-iodophenylalanine, characterized in that in the first reaction step, the carboxy functional group of 4-iodophenylalanine is protected as benzyl ester and the amino group of 4-iodophenylalanine is protected as dibenzyl or benzyloxycarbonyl derivative to yield a protected 4-iodophenyalanine of the following formula 1: where R 1 and R 2 are benzyl, or R 1 is benzyloxycarbonyl and R 2 is H; Bn is benzyl, and then the iodine in the resulting protected 4-iodophenylalanine is substituted with magnesium halogenide by means of a reaction with isopropyl magnesium halogenide stabilized with a complexation base to obtain 4-magnesium halogenide of the protected phenylalanine of the following formula 2: where R 1 and R 2 are the same as in formula 1; and X is Cl or Br; in the second reaction step, 4-magnesium halogenide of the protected phenylalanine obtained in the first reaction step is substituted with boric acid ester of the general formula B(OR 3) 3, to yield a compound of the following formula 3: where R 1 and R 2 are the same as in formula 1; and R 3 is aliphatic alkyl with the number of carbon atoms from 1 to 10, phenyl, or benzyl; and the resulting boronic ester group is hydrolyzed to obtain protected 4-boronophenylalanine of the following formula 4: where R 1 and R 2 are the same as in formula 1; and in the third reaction step, the protected 4-boronophenylalanine obtained in the second reaction step is deprotected by catalytic hydrogenolysis or transfer hydrogenolysis with Pd catalyst and the reaction mixture is then precipitated with bases to obtain 4-boronophenylalanine of the formula 5: in the first reaction step, the carboxy functional group of 4-iodophenylalanine is protected as benzyl ester and the amino group of 4-iodophenylalanine is protected as dibenzyl or benzyloxycarbonyl derivative to yield a protected 4-iodophenyalanine of the following formula 1: where R 1 and R 2 are benzyl, or R 1 is benzyloxycarbonyl and R 2 is H; Bn is benzyl, and then the iodine in the resulting protected 4-iodophenylalanine is substituted with magnesium halogenide by means of a reaction with isopropyl magnesium halogenide stabilized with a complexation base to obtain 4-magnesium halogenide of the protected phenylalanine of the following formula 2: where R 1 and R 2 are the same as in formula 1; and X is Cl or Br; in the second reaction step, 4-magnesium halogenide of the protected phenylalanine obtained in the first reaction step is substituted with boric acid ester of the general formula B(OR 3) 3, to yield a compound of the following formula 3: where R 1 and R 2 are the same as in formula 1; and R 3 is aliphatic alkyl with the number of carbon atoms from 1 to 10, phenyl, or benzyl; and the resulting boronic ester group is hydrolyzed to obtain protected 4-boronophenylalanine of the following formula 4: where R 1 and R 2 are the same as in formula 1; and in the third reaction step, the protected 4-boronophenylalanine obtained in the second reaction step is deprotected by catalytic hydrogenolysis or transfer hydrogenolysis with Pd catalyst and the reaction mixture is then precipitated with bases to obtain 4-boronophenylalanine of the formula 5: