Cyclopentane-based human NK1 antagonists. Part 1: discovery and initial SAR

Area of Science:

• Medicinal Chemistry
• Organic Synthesis
• Pharmacology

Background:

• Human Neurokinin-1 (NK1) receptor antagonists are investigated for therapeutic applications.
• Existing NK1 antagonists, such as morpholine derivatives, face challenges with water solubility.
• Novel chemical scaffolds are needed to improve pharmacokinetic properties of NK1 antagonists.

Purpose of the Study:

• To synthesize a novel cyclopentane scaffold for human NK1 receptor antagonist development.
• To evaluate the water solubility and antagonist properties of the new cyclopentane derivatives.
• To determine the optimal stereochemistry for cyclopentane-based NK1 antagonists.

Main Methods:

• Synthesis of a novel cyclopentane scaffold with three contiguous chiral centers.
• Stereochemical determination of the cyclopentane ring system.
• In vitro evaluation of NK1 receptor antagonist activity and water solubility.

Main Results:

• The novel cyclopentane scaffold 6 yielded low nanomolar human NK1 antagonists.
• These compounds exhibited enhanced water solubility compared to morpholine-based antagonists (1).
• The 1,2-trans-2,3-trans-ring stereochemistry was found to be optimal, surpassing cis-ether/phenyl configurations (1-5).

Conclusions:

• A novel cyclopentane scaffold provides a promising platform for developing potent and soluble human NK1 antagonists.
• The identified optimal stereochemistry is crucial for maximizing antagonist efficacy.
• This work offers a new direction for designing improved NK1 receptor modulators.