Inhibition of plasminogen activator inhibitor (PAI)-1 is useful to treat several disorders including thrombosis. An inhibitor of PAI-1 (TM5275) was newly identified by an extensive study of structure-activity relationship based on a lead compound (TM5007) which was obtained through virtual screening by docking simulations. Its antithrombotic efficacy and adverse effects were tested in vivo in rats and nonhuman primates (cynomolgus monkey). TM5275, administered orally in rats (1 to 10 mg/kg), has an antithrombotic effect equivalent to that of ticlopidine (500 mg/kg) in an arterial venous shunt thrombosis model and to that of clopidogrel (3 mg/kg) in a ferric chloride-treated carotid artery thrombosis model. TM5275 does not modify activated partial thromboplastin time and prothrombin time or platelet activity and does not prolong bleeding time. Combined with tissue plasminogen activator, TM5275 improves the latter's therapeutic efficacy and reduces its adverse effect. Administered to a monkey model of photochemical induced arterial thrombosis, TM5275 (10 mg/kg) has the same antithrombotic effect as clopidogrel (10 mg/kg), without enhanced bleeding. This study documents the antithrombotic benefits of a novel, more powerful, PAI-1 inhibitor in rats and, for the first time, in nonhuman primates. These effects are obtained without adverse effect on bleeding time.

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Chiral phosphinepalladium(II)-catalyzed asymmetric 1,3-dipolar cycloaddition of nitrones to α,β-unsaturated carboxylic acid derivatives has been investigated. In the presence of a catalytic amount of [Pd(NCMe)2{(S)-tolbinap}](BF4)2 [TolBINAP = 2,2‘-bis(di-p-tolylphosphino)-1,1‘-binaphthyl], the reaction of 3-alkenoyl-1,3-oxazolidin-2-ones as dipolarophiles and N-substituted N-benzylidenenitrones has been successfully performed to give isoxazolidine derivatives in high yields with high enantioselectivities. For example, 3-((2,5-dimethyl-3-phenylisoxazolidin-4-yl)carbonyl)-1,3-oxazolidin-2-one was obtained from the reaction of N-benzylidenemethylamine N-oxide and 3-crotonoyl-1,3-oxazolidin-2-one in 89% yield with 60% endo selectivity and 91% ee of the endo isomer. The cycloaddition of N-benzylidenebenzylamine N-oxide and 3-crotonoyl-1,3-oxazolidin-2-one afforded 3-((2-benzyl-5-methyl-3-phenylisoxazolidin-4-yl)carbonyl)-1,3-oxazolidin-2-one in 94% yield with 93% endo selectivity and 89% ee of the endo isomer. Remarkably, the endo/exo selectivity of the products depended on the N-substituent group of the nitrones. These selectivities were explained using molecular modeling.

This paper describes a new method for the highly stereoselective preparation of dithymidine phosphorothioates (TpsT) with the (R) or the (S) configuration at the stereogenic phosphorus atom [(Rp)-or (Sp)-TpsT, respectively], together with the synthesis of oligodeoxyribonucleotides with stereochemically pure phosphate/phosphorothioate mixed backbones through the use of (Rp)-or (Sp)-TpsT as building blocks. Stereochemically pure (Rp)-or (Sp)-TpsT was produced through a five-step process: 1) 1H-tetrazole-promoted thermodynamic equilibration of a diastereomeric mixture of allyl (Rp)-and (Sp)-thymidine 3Ј,5Ј-cyclic phosphate to give the (Sp) isomer as the major component, 2) stereospecific sulfurization of the allyl (Sp)-thymidine 3Ј,5Ј-cyclic phosphate to afford an allyl (Rp)-thymidine 3Ј,5Ј-cyclic phosphorothioate, 3) regioselective and stereoselective methanolysis of the allyl (Rp)-thymidine 3Ј,5Ј-cyclic phosphorothioate to provide an allyl methyl (Rp)-thymidine 3Ј-phosphorothioate as the main

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