Methanesulfonic Acid, often abbreviated as MSA, is the simplest organic sulfonic acid. It consists of a single methyl group bonded to a sulfonic acid group. In the laboratory it is a versatile strong acid used to catalyze organic reactions, form salts, and support a range of electrochemical processes. TCI lists this product (catalog number M0093, CAS 75-75-2) under synthetic reagents in the acids and bases group, because its main role is to supply protons efficiently across many different reaction systems.
Chemists choose MSA because it is a strong acid that is not an oxidizer, unlike concentrated sulfuric acid or nitric acid. As a result, it tends to give cleaner reactions with fewer by-products from unwanted oxidation or sulfonation. This matters when the purity of the target compound and a simple work-up are priorities. MSA dissolves well in water and in many polar organic solvents, and its metal salts are generally highly soluble. That combination makes it an attractive choice for electroplating and other electrochemical work. Because MSA is hygroscopic, careful storage is needed to keep its concentration consistent.
In Indonesia, MSA is used by organic synthesis laboratories at universities and by pharmaceutical R&D units that prepare mesylate salts of active ingredients. It is also used in electrochemistry and metal plating laboratories and by research groups exploring cleaner acid-catalyzed methods. For these users, having a reliable TCI-grade strong acid on hand helps keep experiments reproducible and supports both teaching and development work. Researchers working on salt screening or new catalytic routes also find it a dependable reagent for routine use.
TCI brochures (PDF)
- Sulfonimidoylation Reagent TrNSO 2023-01-30 · p. 1
- Phosphine Ligand for the Synthesis of Sterically Hindered Biaryls HFTPhos 2026-06-18 · p. 2
- Amino Acids and Peptide Synthesis Reagents 2025-08-14 · p. 38
Related TCI products
- TCI B3408 98-11-3 Benzenesulfonic Acid Anhydrous
- TCI B0030 26158-00-9 Benzenesulfonic Acid Monohydrate
- TCI T0751 1493-13-6 Trifluoromethanesulfonic Acid
- TCI T0267 6192-52-5 p-Toluenesulfonic Acid Monohydrate
- TCI P1042 39394-84-8 Phosphorus Pentoxide - Methanesulfonic Acid
- TCI M2059 75-75-2 Methanesulfonic Acid [for HPLC]
- Acid catalysis in organic synthesis: MSA provides strong proton donation without oxidizing sensitive substrates, so esterification, condensation and similar reactions give cleaner products.
- Pharmaceutical mesylate salt formation: R&D laboratories use MSA to convert basic active ingredients into mesylate salts, which helps in studying solubility and handling of drug candidates.
- Electroplating and metal deposition: Metal methanesulfonate salts are generally highly soluble, so MSA-based electrolytes suit plating studies and metal surface finishing research.
- Electrochemical research: MSA's strong acidity, good solubility and non-oxidizing nature make it a useful electrolyte component for laboratory electrochemistry experiments.
- Alternative to oxidizing mineral acids: When sulfuric or nitric acid would cause oxidation or sulfonation side reactions, MSA offers a strong acid option with fewer unwanted by-products.
| Brand | TCI (catalog number M0093) |
|---|---|
| CAS number | 75-75-2 |
| Molecular formula | — |
| Purity | — |
| Category | Chemistry > Synthetic Reagents > Acids, Bases [Synthetic Reagents] |
| Pack sizes | available in TCI standard pack sizes; please confirm the current options with our team |
| Physical form | liquid |
| Storage | hygroscopic; keep the container tightly closed in a dry place |
Store Methanesulfonic Acid in its original, tightly sealed container in a cool, dry, well-ventilated area, away from bases, oxidizers and incompatible materials. Because it is hygroscopic, keep exposure to air short and close the container right after each use so that absorbed moisture does not change its concentration. Use only acid-resistant containers and labware. MSA is a strong, corrosive acid, so handle it in a fume hood while wearing chemical-resistant gloves, safety goggles and a laboratory coat. When diluting, always add the acid slowly to water, never water to acid. Read the TCI Safety Data Sheet before use and follow your institution's chemical waste disposal procedures.
References cited in the TCI brochure
- Gia L. Hoang. Enantioselective Desymmetrization via Carbonyl-Directed Catalytic Asymmetric Hydroboration and Suzuki–Miyaura Cross-Coupling Organic Letters, 2015. doi:10.1021/ol503764d
- Svitlana O. Sotnik. Third Generation Buchwald Precatalysts with XPhos and RuPhos: Multigram Scale Synthesis, Solvent-Dependent Isomerization of XPhos Pd G3 and Quality Control by 1H- and 31P-NMR Spectroscopy Molecules, 2021. doi:10.3390/molecules26123507







