Associate Principal Scientist

Merck; Rahway (NJ); On-site; USD 142,000 - 224,000; Full time

Benefits offered by this job

Medical insurance

Dental insurance

401(k) retirement plan

Paid holidays and vacation

Job summary

Merck, Rahway, NJ, is seeking an Associate Principal Scientist in Process Chemistry to lead flow chemistry and continuous processing efforts across discovery to commercialization. The role focuses on developing scalable API processes for small molecules, macrocyclic peptides, and bioconjugates, with collaboration across synthetic, analytical, and engineering teams.

The candidate will mentor others in flow chemistry, drive technology transfer, and contribute to publications and patents while

Qualifications

• Minimum of 4 years of relevant industrial experience after Ph.D., with demonstrated success in small-molecule process chemistry using flow chemistry.
• Strong experience in organic synthesis, flow chemistry, and continuous processing, including hands-on laboratory experimentation in flow.
• Ability to design, develop, and optimize scalable chemical processes through scientific rigor, creativity, and data-driven problem-solving.

Responsibilities

• Provide scientific leadership for the design, development, and optimization of scalable API processes with emphasis on flow chemistry and continuous processing.
• Lead hands-on laboratory experimentation in flow chemistry to develop robust and efficient chemical transformations and manufacturing processes.
• Influence route design and address complex chemistry, engineering, and manufacturing challenges through mechanistic understanding and data-driven decisions.
• Support process characterization, scale-up, technology transfer, and API campaigns at laboratory, pilot, and manufacturing scales with cross-functional partners.
• Mentor scientists new to flow chemistry and continuous processing to foster scientific excellence and collaboration.
• Contribute to the broader scientific community through publications, patents, and presentations.

Skills

Flow Chemistry

Automation

Organic Synthesis

Process Development

Scientific Leadership

Laboratory Experiments

Chemical Reactors

Flow Cytometry

Education

Ph.D. in Chemistry

Job description

Job Description

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

• Provide scientific leadership for the design, development, and optimization of scalable API processes across multiple development programs, with a strong emphasis on flow chemistry and continuous processing.
• Lead hands‑on laboratory experimentation in flow chemistry to develop robust, sustainable, and efficient chemical transformations and manufacturing processes.
• Influence route design and solve complex chemistry, engineering, and manufacturing challenges through mechanistic understanding, innovative process design, and data‑driven decision‑making.
• Support process characterization, scale‑up, technology transfer, and API campaigns at laboratory, pilot, and manufacturing scales in collaboration with cross‑functional partners.
• Mentor scientists and colleagues new to flow chemistry and continuous processing while fostering a culture of scientific excellence, innovation, and collaboration.
• Contribute to the broader scientific community through publications, patents, presentations, and professional engagement.

Education

Minimum Requirement

• Ph.D. in Chemistry or a related discipline.

Required Experience And Skills

• Minimum of 4 years of relevant industrial experience following completion of a Ph.D., with demonstrated success in small‑molecule process chemistry using flow chemistry.
• Strong experience in organic synthesis, flow chemistry, and continuous processing, including hands‑on laboratory experimentation in flow.
• Proven ability to design, develop, and optimize practical, scalable chemical processes through scientific rigor, creativity, and data‑driven problem‑solving.
• Ability to apply flow chemistry and continuous processing technologies to enable new chemical transformations, influence route design, and address complex process development challenges.
• Experience with automation approaches for continuous‑flow process development is highly valued.
• Demonstrated success working across multidisciplinary teams and effectively communicating technical concepts to scientific and non‑scientific audiences.
• Strong written communication skills, with the ability to prepare clear technical reports, presentations, publications, and documentation.
• Strong self‑initiative, collaborative mindset, and enthusiasm for serving as a subject matter expert in flow chemistry while mentoring others new to the field.
• Demonstrated scientific impact through publications, patents, presentations, or participation in the broader scientific community.

Required Skills

Automation, Chemical Reactors, Flow Chemistry, Flow Cytometry, Innovation, Laboratory Experiments, Organic Chemistry, Organic Synthesis, Production Process Development, Scientific Leadership

US And Puerto Rico Residents Only

Our company is committed to inclusion, ensuring that candidates can engage in a hiring process that exhibits their true capabilities. Please click here if you need an accommodation during the application or hiring process.

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.

Requirements

As an Equal Employment Opportunity Employer, we provide equal opportunities to all employees and applicants for employment and prohibit discrimination on the basis of race, color, age, religion, sex, sexual orientation, gender identity, national origin, protected veteran status, disability status, or other applicable legally protected characteristics. As a federal contractor, we comply with all affirmative action requirements for protected veterans and individuals with disabilities. For more information about personal rights under the U.S. Equal Opportunity Employment laws, visit:
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We are proud to be a company that embraces the value of bringing together, talented, and committed people with diverse experiences, perspectives, skills and backgrounds. The fastest way to breakthrough innovation is when people with diverse ideas, broad experiences, backgrounds, and skills come together in an inclusive environment. We encourage our colleagues to respectfully challenge one another’s thinking and approach problems collectively.
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Salary

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.

Benefits

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.

Location & Work Arrangements

Rahway, NJ, USA
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.