Development of a Green and Sustainable Manufacturing Process for Gefapixant Citrate (MK-7264) Part 2: Development of a Robust Process for Phenol Synthesis

Diversification of Pharmaceutical Manufacturing Processes: Taking the Plunge into the Non-PGM Catalyst Pool

Recent global events have led to the cost of platinum group metals (PGMs) reaching unprecedented heights. Many chemical companies are therefore starting to seriously consider and evaluate if and where they can substitute PGMs for non-PGMs in their catalytic processes. This review covers recent highly relevant applications of non-PGM catalysts in the modern pharmaceutical industry. By highlighting these selected successful examples of non-PGM-catalyzed processes from the literature, we hope to emphasize the enormous potential of non-PGM catalysis and inspire further development within this field to enable this technology to progress toward manufacturing processes. We also present some historical contexts and review the perceived advantages and challenges of implementing non-PGM catalysts in the pharmaceutical manufacturing environment.

Synthetic Approaches to the New Drugs Approved During 2022

In 2022, 23 new small molecule chemical entities were approved as drugs by the United States FDA, European Union EMA, Japan PMDA, and China NMPA. This review describes the synthetic approach demonstrated on largest scale for each new drug based on patent or primary literature. The synthetic routes highlight practical methods to construct molecules, sometimes on the manufacturing scale, to access the new drugs. Ten additional drugs approved in 2021 and one approved in 2020 are included that were not covered in the previous year's review.

Direct Enol Ether Metalation-Negishi Coupling Strategy To Prepare α-Heteroaryl Enol Ethers

A robust direct enol ether metalation-Negishi coupling using heteroaryl halides catalyzed by the palladium-Cy-DPEPhos system is reported. This method, which was demonstrated with a broad substrate scope, is a highly complementary method to the existing Heck coupling of synthesizing challenging α-heteroaryl-α-alkoxy alkenes.

Synthesis of 3,4,5-trisubstituted phenols via Rh(III)-catalyzed alkenyl C-H activation assisted by phosphonium cations

An efficient method for the construction of various 3,4,5-trisubstituted phenol derivatives has been achieved via the Rh(III)-catalyzed coupling of phosphonium cations with internal alkynes. This protocol shows good substrate compatibility, as an array of structurally and electronically diverse phosphonium compounds react efficiently with up to 87% yield.

Catalyst-Tuned Electrophilic Chlorination of Diverse Aromatic Compounds with Sulfuryl Chloride and Regioselective Chlorination of Phenols with Organocatalysts

In this work, we demonstrate that diverse aromatic compounds can be selectively chlorinated through the fine-tuning of the reactivity of sulfuryl chloride (SO₂Cl₂) by organocatalysts. Acetonitrile has been identified to activate SO₂Cl₂ most strongly, thus enabling even chlorination of p-xylene with high yields. 1,4-Dioxane effects chlorination of oxidation-labile aromatic compounds such as p-cresol and 2-naphthol with high yields, 95% and 85%, respectively. An array of potential catalysts has been screened for ortho- and para-selective chlorination of phenols. Thus, we found that acetonitrile, (S)-BINAPO (5 mol %), and diisopropyl ether (4.00 equiv) can catalyze the chlorination of phenols in a para-selective manner (with ≤4:96 o:p ratio), whereas Nagasawa's bis-thiourea (1 mol %), phenyl boronic acid (5 mol %), and (S)-diphenylprolinol (1 mol %) exhibit high ortho selectivity [with ≤99:1 o:p ratio by (S)-diphenylprolinol].

From Powders to Single Crystals: A Crystallographer's Toolbox for Small-Molecule Structure Determination

Although the crystal structures of small-molecule compounds are often determined from single-crystal X-ray diffraction (scXRD), recent advances in three-dimensional electron diffraction (3DED) and crystal structure prediction (CSP) methods promise to expand the structure elucidation toolbox available to the crystallographer. Herein, a comparative assessment of scXRD, 3DED, and CSP in combination with powder X-ray diffraction is carried out on two former drug candidate compounds and a multicomponent crystal of a key building block in the synthesis of gefapixant citrate.