Mild and efficient regioselective surfactant catalyzed deacylation of lipophilic 5-substituted 4-acyl-2-(acylamino)-Δ-1,3,4-thiadiazolines

The most common transport route of biologically active compounds or drugs involves the absorption of the respective compounds across cell membranes via passive diffusion. In this context, biologically active compounds must have sufficient lipophilic character for their penetration through cell membranes. On the other hand, it is a very important task to be able to derivatize the existing compounds with effective and practical transformations to increase their biological activities. Accordingly, the free amino group in the structures of thiadiazolines can be functionalized and their biological activities can be further improved. In the present study, for the first time, several novel lipophilic 5-substituted 4-acyl-2-(acylamino)-Δ-1,3,4-thiadiazolines as potential biologically active agents were synthesized and selectively deacylated with the assistance of urotropin based cationic surfactant to afford the corresponding 5-substituted 4-acyl-2-amino-Δ-1,3,4-thiadiazolines with moderate to good isolated yields. The surfactant catalyzed eco-friendly method developed in this study greatly facilitated the regioselective deacylation of the thiadiazoline ring system at the N position.