2-Nitrosoimino-3,6-dihydro-2H-1,3,4-thiadiazines with antiplatelet and antithrombotic properties

The successful synthesis of 17 nitrosimines of 2 H-1,3,4-thiadiazines is reported. They are best characterized by their electronic spectra (lambda max = 504-522 nm). Some of the compounds were able to inhibit the aggregation of blood platelets in the Born-test (inducer collagen). The most active compound was the 3-nonyl-5-phenyl-derivative 10c which showed an IC50 = 6.5 mumol.l-1. In mesenteric arterioles of rats after p.o. administration (60 mg/kg) a 13% inhibition of thrombus formation is observed. The reason for the rather small effects is the high chemical stability of the title compounds and the fact that decomposition occurs mainly by the evolution of molecular nitrogen. Only small yields of NO are formed.