Synthesis of 5-arylazo-2,4-dithiohydantoins

It was shown that during the interaction between 2-thiohydantoin and P₂S₅ in dioxane 2,4-dithiohydantoin (I) is formed, and without isolation from the reaction solution this compound forms 5-arylazo-2,4-dithiohydantoins (II–XI) with salts of diazone. The structure of two of these compounds has been determined by countersynthesis. When 5-arylazo-2,4-dithiohydantoins interact with amines the corresponding 4-substituted derivatives are formed.