DMSO Technical Articles

Request A Sample Trimethylsulfoxonium bromide (TBM, CAS 25596-24-1) is a crystalline salt made directly from DMSO and methyl bromide. It is the precursor to the Corey–Chaykovsky ylide used to install epoxides and cyclopropanes in pharmaceutical and steroid synthesis, and it sits at the start of several steroid epoxide routes. (CH3)2SO + CH3Br40–80 °C, neat or…

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Request A Sample DMSO accelerates bimolecular substitution by solvating cations while leaving anionic nucleophiles weakly solvated and highly reactive. This bare-nucleophile effect makes it the standard industrial solvent for N-alkylation, cyanide displacement, and thiolate alkylation. R–X + Nu−anhydrous DMSO, 25–120 °C→R–Nu + X− Reaction 1: Bimolecular nucleophilic substitution (SN2) with bare nucleophile in DMSO Mechanism…

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Request A Sample DMSO is chemically stable and low in acute toxicity, but its physical properties set storage and packaging requirements. It freezes at 18.5 °C, is strongly hygroscopic, penetrates the skin, and is incompatible with carbon steel and copper alloys. These properties decide the correct container, warehouse conditions, and transfer hardware. Container and Material…

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Request A Sample The Swern oxidation converts primary and secondary alcohols to aldehydes and ketones using DMSO activated by oxalyl chloride, without any chromium or manganese reagent. It is the standard metal-free oxidation in pharmaceutical synthesis wherever sensitive functional groups must be preserved. RCH2OH + (CH3)2SO + (COCl)2 + 2 Et3N−78 °C, CH2Cl2→RCHO + (CH3)2S…

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Request A Sample Triazole fungicides carry a 1,2,4-triazole ring on a substituted carbon side chain, and installing that nitrogen–carbon bond is the key step. It runs by nucleophilic substitution of a triazolide salt onto an alkyl halide or sulfonate. DMSO is the industry-standard solvent because it solubilizes the triazolide salt at moderate temperatures. The Triazole…

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Request A Sample Statins share a dihydroxyheptanoic acid side chain assembled by condensation or organometallic chemistry. Dimethyl sulfoxide appears at three manufacturing roles across the class: reaction solvent for C–C bond formation, medium for amorphous solid dispersions, and recrystallization solvent for purification. Rosuvastatin Side-Chain Condensation Rosuvastatin calcium attaches its chiral dihydroxyheptenoate side chain by a…

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Request A Sample Steroid hormone APIs are built on a tetracyclic skeleton through 15–30 functional-group-intensive steps. Dimethyl sulfoxide appears at several of them: regioselective acetylation co-solvent, the source and medium for the Corey–Chaykovsky ylide, and a high-boiling medium for oxidation and lactone closure. Reaction Mechanisms and Process Conditions In the regioselective acetylation of dexamethasone, the…

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Request A Sample Nucleophilic aromatic substitution (SNAr) displaces a leaving group on an electron-poor aromatic ring using a phenoxide, alkoxide, amine, or fluoride nucleophile. The ring must carry electron-withdrawing groups such as nitro or cyano ortho or para to the leaving group to stabilize the anionic intermediate. Dimethyl sulfoxide (DMSO) is the dominant industrial solvent…

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Request A Sample Proton pump inhibitors are built around a benzimidazole linked through a sulfoxide bridge to a pyridine. Because the active API is a sulfoxide, every route contains a selective oxidation step, and dimethyl sulfoxide serves as both solvent and oxidant in several industrial processes. The Sulfide-to-Sulfoxide Step The penultimate step oxidizes a 2-[(pyridylmethyl)thio]benzimidazole…

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Request A Sample Several high-volume NSAIDs rely on dimethyl sulfoxide at a decisive synthetic or purification step. The aryl propionic acids ketoprofen and flurbiprofen use it to build their side chains, where solvent choice strongly affects yield. The COX-2 inhibitor celecoxib uses DMSO recrystallization to fix its crystalline polymorph, and diclofenac and naproxen draw on…

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Request A Sample Palladium-catalyzed cross-couplings — Suzuki, Heck, Sonogashira, and Buchwald–Hartwig among them — build the biaryl and C–N bonds at the heart of modern API manufacture. DMSO is the preferred high-temperature solvent when unreactive aryl chlorides or sluggish couplings demand heat that decomposes amide solvents such as DMF. Ar–X + Ar′–B(OH)2Pd(0) cat., K2CO3, DMSO,…

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Request A Sample Methylsulfonylmethane (MSM, dimethyl sulfone, CAS 67-71-0) is a stable, water-soluble sulfone made by oxidizing DMSO. It is the largest downstream derivative of DMSO, consumed mainly as a joint-health supplement, with secondary uses as a high-boiling solvent and chemical intermediate. Both supplement-grade and industrial MSM are outlets for DMSO feedstock. (CH3)2SO + H2O250–90…

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