N.sup.2 -naphthalenesulfonyl-L-arginine derivatives, and the pharmaceutically acceptable acid addition salts thereof

N.sup.2 -naphthalenesulfonyl-L-arginine amides having the formula ##STR95## or the acid addition salts thereof with a pharmaceutically acceptable acid, wherein R.sub.1 and R.sub.2 are members selected from the group consisting of hydrogen and a hydrocarbon selected from the group consisting of alkyl, aryl, cycloalkyl, respectively containing not more than 10 carbon atoms, and aralkyl and cycloalkylalkyl, respectively containing not more than 15 carbon atoms, or R.sub.1 and R.sub.2 together are polymethyleneiminyl of 3-10 carbon atoms, optionally substituted by 1 or 2 alkyl groups containing not more than 10 carbon atoms;

• and R' is a member selected from the class consisting of 5, 6, 7, 8-tetrahydro-1-naphthyl, 5,6,7,8-tetrahydro-2-naphthyl, 1-naphthyl, 2-naphthyl, 1-naphthyl substituted with one member selected from the class consisting of halogen, nitro, cyano, hydroxy, alkyl containing not more than 10 carbon atoms, 2-naphthyl substituted with one member selected from the class consisting of halogen, nitro, cyano, hydroxy and alkyl containing not more than 10 carbon atoms.