Akiyoshi Mochizuki

Design, synthesis, and SAR of cis-1,2-diaminocyclohexane derivatives as potent factor Xa inhibitors. Part II: Exploration of 6–6 fused rings as alternative S1 moieties

A series of cis-1,2-diaminocyclohexane derivatives were synthesized with the aim of optimizing previously disclosed factor Xa (fXa) inhibitors. The exploration of 5-6 fused rings as alternative S1 moieties resulted in two compounds which demonstrated improved solubility and reduced food effect compared to the clinical candidate, compound A. Herein, we describe the synthesis and structure-activity relationship (SAR), together with the physicochemical properties and pharmacokinetic (PK) profiles of some prospective compounds.

Lead optimization of 5-amino-6-(2,2-dimethyl-5-oxo-4-phenylpiperazin-1-yl)-4-hydroxyhexanamides to reduce a cardiac safety issue: discovery of DS-8108b, an orally active renin inhibitor.

With the aim to address an undesired cardiac issue observed with our related compound in the recently disclosed novel series of renin inhibitors, further chemical modifications of this series were performed. Extensive structure-activity relationships studies as well as in vivo cardiac studies using the electrophysiology rat model led to the discovery of clinical candidate trans-adamantan-1-ol analogue 56 (DS-8108b) as a potent renin inhibitor with reduced potential cardiac risk. Oral administration of single doses of 3 and 10 mg/kg of 56 in cynomolgus monkeys pre-treated with furosemide led to significant reduction of mean arterial blood pressure for more than 12 h.

Design and discovery of new (3S,5R)-5-[4-(2-chlorophenyl)-2,2-dimethyl-5-oxopiperazin-1-yl]piperidine-3-carboxamides as potent renin inhibitors

Utilizing X-ray crystal structure analysis, (3S,5R)-5-[4-(2-chlorophenyl)-2,2-dimethyl-5-oxopiperazin-1-yl]piperidine-3-carboxamides were designed and identified as renin inhibitors. The most potent compound 15 demonstrated favorable pharmacokinetic and pharmacodynamic profiles in rat.

2-Aminomethylphenylamine as a novel scaffold for factor Xa inhibitor

We have been researching orally active factor Xa inhibitor for a long time. We explored the new diamine linker using effective ligands to obtain a new attractive original scaffold 2-aminomethylphenylamine derivative. Compound 1D showed very strong in vitro and in vivo factor Xa inhibitory activity, as well as favorable PK profiles in po administration to monkeys.

Design, synthesis and SAR of novel ethylenediamine and phenylenediamine derivatives as factor Xa inhibitors.

We previously reported on a series of cyclohexanediamine derivatives as highly potent factor Xa inhibitors. Herein, we describe the modification of the spacer moiety to discover an alternative scaffold. Ethylenediamine derivatives possessing a substituent at the C1 position in S configuration and phenylenediamine derivatives possessing a substituent at the C5 position demonstrated moderate to strong anti-fXa activity. Further SAR studies led to the identification of compound 30 h which showed both good in vitro activity (fXa IC(50) = 2.2 nM, PTCT2 = 3.9 μM) and in vivo antithrombotic efficacy.

Orally active zwitterionic factor Xa inhibitors with long duration of action.

We have optimized 2-aminomethylphenylamine derivative as a factor Xa inhibitor. Several polar functional groups were introduced in the central phenyl ring, and we focused on zwitter ionic compound showing continuous inhibitory activity in oral administration test. In vitro and oral activities were improved by optimization of S1 and S4 ligands. Incorporating the interaction with S1-β pocket enhanced in vitro factor Xa inhibitory activity to less than 1 nM. Many zwitter ionic compounds showed long duration of action and potent inhibitory activity and high AUC values in oral administration tests to monkeys.