N,N'-(phenylene)dioxamic acids and their esters as antiallergy agents

A series of dialkyl N,N'-(m-phenylene)dioxamates was synthesized by treatment of the requisite m-phenylenediamines with an alkyloxalyl chloride in the presence of triethylamine. Hydrolysis with sodium hydroxide solution gave the corresponding N,N'-(m-phenylene)dioxamic acids. Several N,N'-(p-phenylene)dioxamic acids were synthesized also in the same manner starting with the requisite p-phenylenediamines. These compounds were tested in the rat passive cutaneous anaphylaxis (PCA) assay. When tested iv, activity was found in the N,N'-(m-phenylene) dioxamic acids up to 2500 times that shown by disodium cromoglycate [50% inhibition at 0.001 mg/kg for N,N'-(2-chloro-5-cyano-m-phenylene)dioxamic acid (compound 61)]. Oral activity was seen in this series of compounds with duration of activity up to 120 min. Oral activity was detected in diethyl N,N'-(2-chloro-5-cyano-m-phenylene)dioxamate (compound 38) at levels of drug as low as 0.1 mg/kg.