Since earlier work showed a strong local anesthetic action to be present in 2-(piperidinoethylthio)-benzoxazole and 3-(piperidinoethyl)-2-benzoxazolinone, their derivatives with chlorine or methoxyl in 5- or 6-position were synthesized and pharmacological effect of such a substitution was examined. These substituents were found to markedly increase the surface anesthetic activity but showed no marked effect on filtrative anesthesia.