An efficient protocol is described for the versatile synthesis of novel dihydrothiazol-2-yl-amide derivatives via the regioselective 5-exo-dig heterocyclisation of N-propargyl carbamothioyl-amides in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) in refluxing ethanol. All products were obtained in good yields and short reaction time (10–30 min).