Matrix metalloproteinases (MMPs) are a family of zinc endopeptidases that have been implicated in various disease processes. Different classes of MMP inhibitors, including hydroxamic acids, phosphinic acids and thiols, have been previously described. Most of these mimic peptides and most likely bind in a similar way to the corresponding peptide substrates. Here we desccribe pyrimidine-triones as a completely new class of metalloprotease inhibitors. While the pyrimidine-trione template is used as the zinc-chelating moiety, the substituents have been optimized to yield inhibitors comparable in their inhibition efficiency of matrix metalloproteinases to hydroxamic acid derivatives such as batimastat. However, they are much more specific for a small subgroup of MMPs, namely the gelatinases (MMP-2 and MMP-9).

Improved procedures for large scale preparation of oxy-substituted isoquinolines are reported. Moreover, a simple and convenient protocol for alkaline work-up of titanium containing reaction mixtures is given, which is expected to be of general interest even for reactions on a technical scale.

Based on the structures of aminopyridine thrombin inhibitors (1), a series of aminoalkyl- and guanidinoalkyl-substituted diarylsulfonamides were prepared. The most potent derivative, N-[3-(4-guanidinobutoxy)-5-methyl-phenyl]-benzenesulfonamide (6c) had Ki = 0.18 microM for thrombin and did not inhibit trypsin, plasmin, or factor Xa. Comparison of the X-ray structures of the thrombin/1b and the thrombin/6c complexes revealed important aspects which govern the binding of such diarylsulfonamides to thrombin.

Derivatives of (2-amidino-1,2,3, 4-tetrahydro-isoquinolin-7-yloxy)phenylacetic acid (TIPAC) were developed as inhibitors of factor Xa (fXa). The compounds are prepared using 15 synthetic steps on average. The most potent compounds (14, 17, 22-26) display inhibition constants of Ki = 21-55 nM but do not inhibit thrombin (Ki = 5->100 microM) and only weakly inhibit trypsin (Ki = 0.08-5 microM). They bear a second basic moiety, e.g., substituted 1-(iminomethyl)piperidines, which is linked to C-4 of the phenyl group of TIPAC via an oxygen atom. The inhibition constants of these compounds are almost independent of the size of the (iminomethyl)piperidine substituent. Due to the fact that fXa displays two cation binding sites, namely, the S1 and S4 sites, in principle two binding modes are conceivable for the novel dibasic fXa inhibitors. Molecular modeling experiments based on the X-ray structures of uninhibited fXa and the DX-9065a/fXa complex were carried out. The results taken together with the inhibition constants clearly favor one binding mode: the tetrahydro-isoquinoline fills the S1 pocket even better than the naphthalene moiety of DX-9065a, and the (iminomethyl)piperidine residues occupy the S4 site.

During screening for novel thrombin inhibitors it was discovered that the 4-aminopyridine derivative 1 inhibits human α-thrombin competitively and selectively. The 4-aminopyridine moiety itself is most likely the major determinant of the selectivity due to the increased hydrophobicity of the S1 pocket in thrombin compared to trypsin and plasmin. Optimization led to the selective thrombin inhibitor 14 with an inhibition constant, Ki of 70 nM. © 1997 Elsevier Science Ltd.

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We describe a new, efficient synthesis of DX-9065 a (4), a potent inhibitor of the blood coagulation enzyme factor Xa (fXa) which has previously been prepared in more than 20 steps. We saved approximately 10 step starting with a Pd-catalyzed cyanation of the triflate 10 of 7-methoxynaphthalen-2-ol (9). After cleavage of the MeO group with boron tribromide. the triflate 6 was coupled to acrylate 5 in a Heck reaction (--> 3). The subsequent transformations led to DX-9065 a.