Syntheses of N 1 -Acyl-4-acetaminonaphthalenesulfonamide-1. III: Some Condensing Agents for Synthesis of N 1 -Acyl-4-acet-aminonaphthalenesulfonamide-1@@@N 1 -Acyl-4-acetaminonaphthalenesulfonamideの合成に際する縮合剤について