The solution-phase parallel synthesis involving reactions of Baylis-Hillman products of 3-substituted -5-isoxazolecarb-aldehydes with nucleophiles and their in vivo antithrombotic evaluations are described along with the results of in vitro platelet aggregation inhibition assay of a few compounds. Results of the detailed evaluation of one of the compounds as an inhibitor of platelet aggregation are also presented. (C) 2004 Elsevier Ltd. All rights reserved.