(Senior / Principal) Scientist, Organic Chemistry

Capable Labs • San Francisco, CA

3d • Onsite

About The Position

We are a vibrant and intensely mission-driven team in San Francisco, comprising members from MIT, Harvard Medical School, Roche, ETH, and Dana-Farber. We value speed and rigor, coupled with excitement, drive, and a strong work ethic. In an early-stage environment, we value people who can bring clarity to open-ended problems, take ownership of the next steps, and follow through with energy. Capable Labs is a place for ambitious, high-integrity people who want to become dramatically better. You will be surrounded by people who care intensely about the work, get close feedback from the people making scientific and company-defining decisions, and have room to own increasingly important problems. We believe excellent work should be met with meaningful reward, ownership, and trust. Responsibility is earned through contribution, not title alone: anyone who demonstrates the judgment, rigor, and follow-through to move important work forward can earn meaningful scope. About the Role You will lead synthetic execution across Capable’s small-molecule, peptide, and adjacent therapeutic programs. You will turn target structures into confirmed, test-ready compounds by choosing practical routes, solving difficult reaction and purification problems, and building reliable chemistry workflows. This is a senior hands-on role centered on excellent synthesis and material delivery.

Requirements

• Five or more years of hands-on industry experience in synthetic organic, medicinal, peptide, or closely related chemistry; peptide experience is helpful but not required.
• Strong synthetic judgment and the ability to turn a target structure into a confirmed, biologically testable compound.
• Experience owning route selection, purification, characterization, quality control, documentation, and biological handoff.
• Deep troubleshooting ability across reactions, purification, analytical methods, and laboratory instrumentation.
• Comfort working close to biological readouts while keeping primary ownership of practical chemistry execution.
• The ability to provide technical direction, improve team workflows, and remain directly involved in the hardest experiments.

Nice To Haves

• peptide experience is helpful but not required

Responsibilities

• Lead organic-chemistry execution from target-compound selection through route design, synthesis, purification, characterization, quality control, and biological handoff.
• Design and execute practical routes using solution-phase and solid-phase methods, functional-group transformations, coupling chemistry, protecting-group strategies, and late-stage diversification.
• Own the delivery of the right compounds with confirmed identity, purity, yield, documentation, and readiness for biological testing.
• Operate and help maintain key chemistry instrumentation, including HPLC, prep HPLC, LC-MS, microwave-assisted synthesis systems, and related platforms.
• Resolve difficult synthetic and analytical issues involving failed reactions, conversion, selectivity, side products, deprotection, solubility, purification, recovery, and instrument downtime.
• Work with biology and pharmacology teams to prioritize compounds using SAR, potency, stability, exposure, tolerability, and efficacy data while remaining anchored in practical chemistry execution.
• Improve routes, analytical methods, documentation, and laboratory workflows so high-quality material can be produced faster and more reliably.

Benefits

• generous equity options
• $500+ monthly wellness budget for training, supplements, coaching, recovery, or other tools that help you perform at your best.
• Healthcare: We offer a broad range of medical, dental, and vision coverage options, with Capable covering 100% of the base policy.
• HSA, FSA, and 401K plans.
• Healthy dinners with the team are provided daily.
• visa sponsorship where appropriate, including O-1, H-1B, J-1, TN, and other employment-based pathways.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed