Associate Principal Scientist, Process Chemistry
The Process Chemistry organization, located at our Rahway, NJ site, is seeking a highly motivated and accomplished scientist with deep expertise in flow chemistry and continuous processing to join the Catalysis and Flow Lab. This position offers an opportunity to play a key role in advancing our pipeline of drug substances, including small molecules, macrocyclic peptides, and bioconjugates, by developing and implementing robust, sustainable, and efficient API manufacturing processes from discovery through commercialization.
The successful candidate will lead laboratory experimentation in flow chemistry, develop and implement novel continuous processing technologies, enable new chemical transformations, and influence route design across development programs. The role requires close collaboration with multidisciplinary teams, including synthetic and analytical chemists, chemical engineers, manufacturing partners, and other stakeholders, to support API campaigns at laboratory, pilot, and manufacturing scales. Responsibilities also include solving complex chemistry and processing challenges, supporting technology transfer, mentoring scientists new to the field, and contributing to the external scientific community through publications, patents, presentations, and professional engagement.
The ideal candidate will possess strong expertise in synthetic organic chemistry, process development, flow chemistry, and continuous processing, along with the passion and capability to serve as a subject matter expert within the Process Chemistry Department. A proven record of scientific innovation, technical achievement, self-initiative, and effective collaboration in a dynamic team environment is essential.
Specific Responsibilities
Education
Minimum Requirement
Required Experience and Skills
Required Skills:
Automation, Chemical Reactors, Flow Chemistry, Flow Cytometry, Innovation, Laboratory Experiments, Organic Chemistry, Organic Synthesis, Production Process Development, Scientific Leadership
Preferred Skills:
Current Employees apply HERE
Current Contingent Workers apply HERE
US and Puerto Rico Residents Only:
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The salary range for this role is
$142,400.00 - $224,100.00
This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. An employee’s position within the salary range will be based on several factors including, but not limited to relevant education, qualifications, certifications, experience, skills, geographic location, government requirements, and business or organizational needs.
The successful candidate will be eligible for annual bonus and long-term incentive, if applicable.
We offer a comprehensive package of benefits. Available benefits include medical, dental, vision healthcare and other insurance benefits (for employee and family), retirement benefits, including 401(k), paid holidays, vacation, and compassionate and sick days. More information about benefits is available at https://jobs.merck.com/us/en/compensation-and-benefits
You can apply for this role through https://jobs.merck.com/us/en (or via the Workday Jobs Hub if you are a current employee). The application deadline for this position is stated on this posting.
San Francisco Residents Only: We will consider qualified applicants with arrest and conviction records for employment in compliance with the San Francisco Fair Chance Ordinance
Los Angeles Residents Only: We will consider for employment all qualified applicants, including those with criminal histories, in a manner consistent with the requirements of applicable state and local laws, including the City of Los Angeles’ Fair Chance Initiative for Hiring Ordinance
Search Firm Representatives Please Read Carefully
Merck & Co., Inc., Rahway, NJ, USA, also known as Merck Sharp & Dohme LLC, Rahway, NJ, USA, does not accept unsolicited assistance from search firms for employment opportunities. All CVs / resumes submitted by search firms to any employee at our company without a valid written search agreement in place for this position will be deemed the sole property of our company. No fee will be paid in the event a candidate is hired by our company as a result of an agency referral where no pre-existing agreement is in place. Where agency agreements are in place, introductions are position specific. Please, no phone calls or emails.
Employee Status:
Regular
Relocation:
No relocation
VISA Sponsorship:
No
Travel Requirements:
10%
Flexible Work Arrangements:
Not Applicable
Shift:
1st - Day
Valid Driving License:
Yes
Hazardous Material(s):
N/A
Job Posting End Date:
08/31/2026
*A job posting is effective until 11:59:59PM on the day BEFORE the listed job posting end date. Please ensure you apply to a job posting no later than the day BEFORE the job posting end date.

At MSD, known as Merck & Co., Inc., Rahway, NJ, USA in the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit www.msd.com and connect with us on Facebook, Instagram, Twitter, and YouTube.