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.