In multistep drug total synthesis, strong acid catalysts often take a toll on sensitive acetal, epoxide, and glycosidic structures, while the selective management of protecting groups is critical to process success. Pyridinium p-toluenesulfonate (PPTS, CAS: 24057-28-1), with its mild and controllable acid release, has become a trusted catalyst in the construction of complex molecules. Shunxiang

Pyridine hydrobromide (CAS 18820-82-1), molecular formula C₅H₅N·HBr, molecular weight 160.01 g/mol, EC number 242-600-7, is a white to off-white hygroscopic crystalline solid that melts around 216–219 °C with decomposition. It is prepared by the classic equimolar acid-base neutralization:C₅H₅N + HBr → [C₅H₅NH]⁺ Br⁻ Under an ice bath, hydrobromic acid is added dropwise to a solution

Di-tert-butyl dicarbonate (Boc₂O, CAS: 24424-99-5) is often simply described as an “amine protecting reagent,” but in the eyes of pharmaceutical R&D engineers, it is the driving force behind numerous blockbuster drugs. Shunxiang Pharmaceutical has combed through publicly available data from overseas journals and patents to show how this classic reagent underpins the synthetic routes of several

When calculating catalyst costs, many companies only look at unit price—overlooking the hidden expenses of strong acid catalysis: impurities from over-reaction, solvent wasted on repeated recrystallization, labor hours spent on column chromatography, and yield losses from side reactions. Combined, these often cost far more than the catalyst itself.   Pyridinium p-Toluenesulfonate (PPTS, CAS 24057-28-1) is

Pyridinium tribromide, also known as pyridinium bromide perbromide (PHPB), CAS No. 39416-48-3, has the molecular formula C5H6Br3N and a molecular weight of 319.82. It is an orange-red to reddish-brown crystalline powder, melting at approximately 127–133 °C with decomposition. Composed of a pyridinium cation and a tribromide anion, it decomposes in water but is soluble in

Di-tert-butyl azodicarboxylate (DBAD, CAS No. 870-50-8) in emerging synthetic fields. As a highly electrophilic azo reagent, DBAD continues to demonstrate unique value in cutting-edge directions such as C-H functionalization, aerobic oxidation, and flow photochemistry, thanks to the steric effect of its tert-butyl groups and the distinctive reactivity of its N=N double bond. I. Palladium-Catalyzed C-H

In traditional sulfonation reactions, reagents such as chlorosulfonic acid, fuming sulfuric acid, and liquid sulfur trioxide are highly corrosive, prone to moisture absorption, and react violently. These not only pose significant operational risks but also often lead to issues like over-sulfonation and functional group degradation—particularly in pharmaceutical intermediates and fine chemical synthesis, where “excessive sulfonation”

Diisopropyl azodicarboxylate (DIAD, CAS No. 2446-83-5) beyond the classic Mitsunobu reaction. As a highly electrophilic azodicarboxylate ester, DIAD continues to demonstrate value in emerging synthetic fields such as photocatalytic C-H functionalization and dehydrogenative heterocycle construction, thanks to the unique reactivity of its N=N double bond. I. Efficient Dehydrogenating Reagent in Quinoline Synthesis According to Organic

In recent years, GLP-1 peptide drugs like semaglutide have taken the market by storm, driving the entire peptide synthesis sector to new heights. Behind every peptide synthesis route, one reagent quietly performs a critical task—putting on and taking off “protective suits” for amino groups. That reagent is di-tert-butyl dicarbonate, better known in the industry as

In modern pharmaceutical industry, behind the journey of a drug from the lab to the production line, there often stand dozens of seemingly inconspicuous chemical intermediates. Hydrochloride salt of pyridine (CAS: 628-13-7) is one of them—it does not directly treat diseases or save lives like active pharmaceutical ingredients, yet it plays an irreplaceable “reaction switch”