The synthesis and some reactions OF 3-(2-aminophenyl)-2-iminothiazolidines. ring closure of n-(2-thiocyanaoethyl,)-ophenylenediamines; thiazolidine vs. 3,1,6-benzothiadiazocine formation

When treated with strong acids, the N-(2-thiocyanatoethyl)-o-phenylenediamines (1g-1v) are cyclized exclusively to 3-(2-aninophen- yl)-2-iminothiazolidines (6) while the related tertiary amines (1a-1f) gave, under the same conditions, benzothiadiazocines of types (2) or (3). Some of the type (6) compounds are highly active antidepressants of low toxicity. Thermal reactions of compound (6b) and its conversion into tricyclic compounds of types (22) and (24) are also reported.