Summary
Overview
Work History
Education
Skills
Timeline
Publications
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Benjamin Johnson

San Diego,USA

Summary

Accomplished professional with extensive industry experience and a proven track record in the advancement of early-stage hits to clinical candidates. Experienced in drug design and synthesis of novel drug molecules via SAR-driven lead optimization with a comprehensive knowledge of analytical and purification techniques. Expert in synthetic organic chemistry, including complex molecule synthesis via multi-step, multi-component and parallel synthesis techniques. Played key roles in projects leading to the publication of several patents and papers in major scientific journals.

Overview

22
22
years of professional experience

Work History

ASSOCIATE SCIENTIST

Takeda Pharmaceuticals
09.2020 - 07.2024
  • Optimized key properties of a published compound to develop a tool compound for the initiation of a new project to develop antagonists for the treatment of Alzheimer’s disease.
  • Followed up on HTS hits to deliver lead compounds with desired profile to be advanced into candidate nomination status.
  • Shortened the synthetic route of a key building block of an Orexin agonist by several steps. The optimized route allowed faster analog synthesis, improved synthetic tractability, and was highly scalable with the desired enantioselectivity.
  • Leveraged medicinal chemistry knowledge to mitigate toxicity risks by lowering CYP TDI inhibition of Orexin agonists and mitigate phototoxicity risks by reducing conjugation in splicing modulators of the mutant Huntington gene.
  • Acquired project management experience, such as advancing compounds through appropriate assays, coordinating with multiple departments, and collaborating with CROs.

SENIOR RESEARCH ASSOCIATE

Takeda Pharmaceuticals
06.2016 - 09.2020
  • As part of a two-person team, established a High Throughput Medicinal Chemistry group at the Takeda, San Diego site. Libraries of compounds were made in a parallel fashion to support several projects over multiple Takeda sites.
  • Managed and maintained Shimadzu HPLC and Waters UPLC/SFC instruments.
  • Played a pivotal role in designing and equipping chemistry labs at Takeda’s newly constructed San Diego site.

RESEARCH ASSOCIATE II

Takeda Pharmaceuticals
08.2012 - 06.2016
  • Using Structure-Based Drug Design (SBDD) in parallel with the deconstruction of a published compound, a novel series of ASK1 inhibitors was optimized with excellent selectivity and desirable drug-like properties.

SYNTHETIC CHEMIST (Contract Position)

Pfizer Global R&D
11.2011 - 08.2012
  • Performed reaction optimization screens under inert conditions in a glovebox. Reactions were analyzed by HPLC then optimized conditions were relayed to medicinal chemists for analog synthesis.

SENIOR RESEARCH ASSOCIATE

Arena Pharmaceuticals
12.2009 - 01.2011
  • Devised a new enantioselective synthesis for an optimized scale-up procedure of a chiral tricyclic indole for an exploratory drug candidate of the S1P1 receptor. The enantioselective synthesis involved screening several phosphine ligands to selectively reduce an unsaturated ester via a 1,4-hydride addition using PMHS as a hydride source with a metal salt/phosphine catalytic complex.
  • Gained experience working in a development lab using 20L vertical reactors to scale up over 200g of the S1P1 exploratory drug candidate using the optimized enantioselective synthesis with a final e.e. greater than 98%.

RESEARCH ASSOCIATE III

Arena Pharmaceuticals
10.2006 - 12.2009
  • Helped initiate a backup project to discover agonists of the CB2 receptor. Devised a procedure of using the company database of in-house compounds to filter out unlikely agonists of the CB2 receptor, leaving about 100 possible hits, which were screened, and 20 were found to have activity in the nanomolar range.
  • Designed and optimized the synthesis of a series of pyrazoles as potent agonists of the CB2 receptor with no activity on the CB1 receptor.

RESEARCH ASSOCIATE II

Arena Pharmaceuticals
08.2004 - 10.2006
  • Synthesized novel bicyclic pyrazoles as agonists of the GPR109a (Niacin) receptor for the treatment of hypocholesterolemia. This series led to clinical candidate MK-1903.

RESEARCH ASSOCIATE I

Arena Pharmaceuticals
08.2002 - 08.2004
  • Synthesized analogs of Acifran as agonists of the GPR109a (Niacin) receptor for the treatment of hypocholesterolemia.

Education

Bachelor of Science (B.S.) - Chemistry and Biochemistry (Joint Honors)

University of Wales

Skills

  • Drug Design
  • Organic Synthesis
  • Hit-to-lead optimization
  • Chromatography
  • Parallel synthesis
  • Analytical chemistry
  • NMR
  • SFC
  • HPLC
  • LCMS
  • SBDD
  • Photoredox chemistry
  • SciFinder
  • ChemDraw
  • Schrodinger Software
  • Microsoft
  • Spotfire

Timeline

ASSOCIATE SCIENTIST

Takeda Pharmaceuticals
09.2020 - 07.2024

SENIOR RESEARCH ASSOCIATE

Takeda Pharmaceuticals
06.2016 - 09.2020

RESEARCH ASSOCIATE II

Takeda Pharmaceuticals
08.2012 - 06.2016

SYNTHETIC CHEMIST (Contract Position)

Pfizer Global R&D
11.2011 - 08.2012

SENIOR RESEARCH ASSOCIATE

Arena Pharmaceuticals
12.2009 - 01.2011

RESEARCH ASSOCIATE III

Arena Pharmaceuticals
10.2006 - 12.2009

RESEARCH ASSOCIATE II

Arena Pharmaceuticals
08.2004 - 10.2006

RESEARCH ASSOCIATE I

Arena Pharmaceuticals
08.2002 - 08.2004

Bachelor of Science (B.S.) - Chemistry and Biochemistry (Joint Honors)

University of Wales

Publications

  • Analogues of Acifran: Agonists of the High and Low Affinity Niacin Receptors GPR109a and GPR109b. J.Med.Chem. 2007, 50, 1445-1448.
  • Agonist lead identification for the high affinity niacin receptor GPR109a. Bioorganic & Medicinal Chemistry Letters, 17, (2007), 4914-4919.
  • Potent tricyclic pyrazole tetrazole agonists of the nicotinic acid receptor (GPR109a) Bioorganic & Medicinal Chemistry Letters 20 (2010) 2797-2800.
  • 4-Oxo-4,5-dihydro-furan-2-carboxylic acid derivatives, and methods of treatment of metabolic-related disorders thereof. Patent No. WO2005/051937 A2
  • 3H-imidazo[4,5-b]Pyridin-5-ol derivatives useful in the treatment of GPR81 receptor disorders. Patent No. WO2010/030360
  • Modulators of the Sphingosine-1-Phosphate (S1P) receptor useful for the treatment of disorders related thereto. Patent No. WO2010/100295 A1
  • Process for the preparation of S1P1 receptor modulators and crystalline forms thereof. Patent No. WO 2011/109471 A1
  • Preparation of benzoyloxytetrahydropyridindole derivatives and analogs for use as sphingosine-1-phosphate receptor modulators. Patent No. WO2011005295 A1
  • Structure-based drug design of novel ASK1 inhibitors using an integrated lead optimization strategy. Bioorganic & Medicinal Chemistry Letters (2017), 27(8), 1709-1713
  • Complementary Asymmetric Routes to (R)-2-(7-Hydroxy-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate. Organic Letters (2012), 14(24), 6306-6309
  • (1aR,5aR)-1a,3,5a-Tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene-4-carboxylic Acid (MK-1903): A Potent GPR109a Agonist that Lowers Free Fatty Acids in Humans. Journal of Medicinal Chemistry (2012), 55(8), 3644-3666
  • N-Heteroarylalkyl-2-(heterocyclyl and heterocyclylmethyl) acetamide derivatives as SST4R agonists and their preparation. Patent No. WO2012120781 A1
  • Structure-guided optimization of a novel class of ASK1 inhibitors with increased sp3 character and an exquisite selectivity profile. Bioorganic & Medicinal Chemistry Letters (2020), 30(17), 127405
  • Preparation of piperidinyl 3-(aryloxy)propanamides and 3-(aryloxy)propanoates as SST4R modulators. Patent No. WO2019169153 A1
  • Design and synthesis of new tricyclic indoles as potent modulators of the S1P1 receptor. Bioorganic & Medicinal Chemistry Letters (2015), 25(3), 659-663
  • (7-Benzoyloxy-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetic Acids as S1P1 Functional Antagonists. ACS Medicinal Chemistry Letters (2014), 5(12), 1334-1339
  • Macrocyclic heterocyclic compounds and use thereof. US Non-Provisional Patent Application filed on March 15, 2024 (U.S. App. No. 18/606,857).

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