Nineteen different-compounds were synthesized and some of their pharmacological properties as local anesthetic activities, analgetic activities, antibiotic activities, acute toxicities, influences on blood pressure-were investigated. Three of them were found to have a longer action in both topical and infiltratic anesthesia than Lidocaine. The duration of infiltratic anesthesia of compounds No. 1, 14, 18 were three times as long as Lidocaine. The conductive anesthetic and recovery processes of sample No. 1 tested on bullfrog sciatic nerve were similar to those of Lidocaine. The recovery of dichloro-derivatives was inferior to that of monochloro-derivatives. In general acute toxicities of these compounds increased as the number of carbon atoms in diamino-radicals increased. Almost all of these compounds showed on the hot plate test remarkable elevation of pain threshold when 70 mg were injected to mice. Blood pressure of the dog was depressed temporarily and slightly by administration of 1 to 3 mg of these substances, but no antimicrobial activity was observed.
