Research Associate/Sr. Research Associate/ Scientist 1, Chemistry (ChemRA0004)

South San Francisco, California
Commensurate with qualifications and experience
Aug 03, 2018
Science/R&D, Chemistry
Required Education
Bachelors Degree
Position Type
Full time

Circle Pharma is an emerging biotech company discovering and developing macrocycle therapeutics targeting important intracellular protein-protein interactions. Our novel, intrinsically cell-permeable macrocycles provide a unique opportunity to address these “undruggable” targets.  Our first targets are in molecularly defined cancers, with future expansion to other therapeutic areas. 

We are a tightly integrated team of synthetic and computational medicinal chemists and pre-clinical biologists. Our discovery platform includes structure based design, integrating target affinity, cell permeability and medicinal chemistry, and automated macrocycle synthesis. We have open positions for candidates who want to make key contributions to a small, exciting startup company and help drive its growth.  For more information about Circle Pharma, see our website at

Job Description

We are seeking a highly skilled and motivated Research Associate, Senior Research Associate or Scientist with a strong background in synthetic organic chemistry to join our expanding medicinal chemistry department. This individual will engage in drug discovery enabled by our computational/medicinal chemistry and biology group. Specifically, they will synthesize small molecules with novel heterocyclic cores optimized for potency, PK-ADME and in vivo efficacy as part of our macrocycle chemistry synthesis team.  

Key Responsibilities

  • Design and executemultistep organic syntheses of small molecules and deliver final compounds with high purity
  • Work closely with colleagues to plan efficient synthetic pathways
  • Support the process team by assisting in the solid-phase synthesis of Circle’s membrane permeable macrocycles
  • Coordinate with CRO chemistry teams

Minimum Requirements

  • B.S. or M.S. in synthetic organic chemistry with at least 3-5 years of experience in small molecule discovery and development in the biotech/pharmaceutical industry (RA / Sr. RA) or PhD in synthetic organic chemistry with at least 2 years of relevant post-doctoral experience, preferably in industry (Scientist 1)
  • Experience and expertise in the use of modern synthetic organic techniques for small molecules
  • High level of creativity, knowledge of reaction mechanisms, and strong synthetic problem-solving skills, including identifying multiple synthetic approaches to a given compound
  • Experience with process scale solution-phase synthesis
  • Experience with microwave chemistry, inert atmosphere techniques, organometallic cross coupling reactions and analytical techniques, NMR, LC-MS, RP-HPLC, flash chromatography, recrystallization, and distillation
  • Possess a strong desire to learn new techniques and incorporate new methodologies
  • Proficient in the use of Microsoft Office, ChemDraw, MestReNova and with Mac/PC operating systems
  • Excellent written and documentation skills
  • Excel at maintaining laboratory record of scientific findings
  • Excellent record at maintaining laboratory safety standards
  • Strong organizational, communication, and interpersonal skills 
  • Self-motivated, independent, and have the ability to work with minimal supervision
  • Team-oriented and work well in collaborative environments 
  • Enjoy operating in an exceptionally dynamic, high-achieving and cooperative environment where every voice matters
  • Able to stand for extended periods of time and lift 20 pounds comfortably

Circle Pharma is a dynamic start-up company, and the successful candidate must have the ability and desire to work in a fast-paced environment. Circle offers a comprehensive compensation package, as well as generous paid time off in addition to Company observed holidays.  The Company provides Medical, Dental and Vision Insurance, along with a retirement savings plan which includes employer contributions.  We promote a culture in which employees are respected and rewarded for hard work, innovation, personal initiative, and teamwork. 

Circle Pharma is an equal opportunity employer and committed to a diverse workplace. All applicants will be considered equally without regard to race, color, ethnicity, veteran status, religion, national origin, marital status, political affiliation, age, sex, sexual orientation, handicapping condition, membership in an organization or any other non-merit factors.

Qualified candidates are encouraged to submit a Resume/CV and cover letter to Cayla McEwen via email at and please refer to job code ChemRA0004 in the subject line. No phone calls please. Direct applicants only.