Synthesis, structural characterization and thromboxane A2 receptor antagonistic activity of 3-substituted 2-[(arylsulfonyl)imino]-2,3-dihydrothiazolyl derivatives

A series of new 2-[(arylsulfonyl)imino]-2,3-dihydrothiazolyl derivatives substituted on the heterocyclic N by a phenoxyacetic moiety was prepared according to a Hantzsch's synthesis between N, N'-disubstituted thioureas and chloroacetaldehyde. The regiochemistry of the cyclocondensation reaction was established by high resolution NMR methods. Potential thromboxane A2/prostaglandin H2 (TxA2/PGH2) receptor antagonism was evaluated using human platelet aggregation assays and radioligand binding studies. The results showed that the affinity for the TxA2/PGH2 receptor was strongly dependent on the position of the oxyacetic acid side chain. On the basis of the X-ray crystal analysis of compound 9f, a molecular modelling was undertaken on compounds 3d, 3e, and 3f. Comparison with the 3D structure of sulotroban was discussed.