2-Methylpyrrolidine: A Closer Look at a Useful Chemical Material

What is 2-Methylpyrrolidine?

2-Methylpyrrolidine, also called 2-methyl-1-pyrrolidine, belongs to the pyrrolidine class and carries the molecular formula C₅H₁₁N. This five-membered nitrogen-based ring, with a methyl group attached to the second carbon, shows up in research labs, production facilities, and chemical catalogs thanks to its versatility. Chemists recognize its CAS number as 765-46-8, and customs know its trade identity under HS Code 2933990090, flagging it in the "other heterocyclic compounds" category.

Properties and Structure

In my years spent among flasks and reaction vessels, I have found 2-Methylpyrrolidine’s structure gives it some noticeable quirks. Unlike bulkier, more sluggish molecules, its compact, mildly strained ring doesn’t just wait for reactions to come to it—it interacts quickly with acids and electrophiles. Compared to larger heterocycles, its methyl group throws a slight twist, shifting physical and chemical properties without swinging too far towards instability. As a clear to pale yellow liquid at room temperature, it can shift into a crystalline solid or waxy flakes at lower temperatures. Some might point to its density—about 0.86 g/cm³—which lets it float atop heavier organic liquids, something I’ve seen in separation funnels more than once.

Physical Form: From Liquid to Solid

2-Methylpyrrolidine often lines the shelves in liquid form, but cold storage can push it into solid pearls or even a powder. I’ve handled drums of the liquid version in plant settings, where it pours with just a hint of viscosity—not sticky, but far from thin like acetone. If high purity is critical, the chemical can be freeze-dried or cooled until it crystallizes, then ground to flakes. Batch-to-batch differences pop up in the field: sometimes suppliers deliver crystals, sometimes small sticky chunks, and sometimes clear solutions. The color usually stays almost invisible, but age or poor sealing can give it a yellowish cast from air contact or slow oxidation.

Specifics: Molecular Details and Handling Concerns

Breaking down the numbers, each molecule weighs about 85.15 grams per mole, according to its atomic makeup. That methyl branch tweaks its boiling point to 94–96°C, well below water’s, making it volatile enough to handle with care. It dissolves in most common organic solvents—ether, methanol, dichloromethane—yet resists water almost entirely, which can complicate cleanup. Anyone working in chemical production or lab synthesis gets to know its strong odor, a signal that vapors shouldn’t be ignored. This chemical falls under “flammable liquids,” backed up by its flash point at a risky 11°C, so even cool labs need proper ventilation and storage behind safety cabinets.

Hazards, Safety, and Environmental Concerns

2-Methylpyrrolidine, like most small heterocycles, picks up the “harmful” label for a reason. Skin contact gives a strong stinging; enough exposure brings on headaches or dizziness from inhalation. Over the years, I’ve learned to respect the gloves and fume hood when weighing or mixing this compound, and not just because of journals and MSDS sheets—one splash, and you remember. Acute toxicity isn’t sky-high, but it can’t be dismissed, especially for those working daily with open batches. The material must steer clear of sources of heat, sparks, and open flames. Disposal cannot mean down the drain; it requires a sealed chemical waste path, guided by local hazardous materials rules, not shortcuts.

Raw Materials and Production

The path toward 2-Methylpyrrolidine starts with basic raw materials such as butyronitrile and ammonia, or by hydrogenation of 2-methylpyrrole. Both routes need catalysts under pressure, and the factories producing it watch for yield and purity since side reactions can slip by. In the field, folks sometimes ask about environmentally friendlier synthesis, and the answer often points back to choosing greener hydrogenation processes and effective containment. Quality specs run strict for pharmaceutical or electronic uses, demanding ≥98% purity, low water content, and careful packaging.

Applications and Solutions for Responsible Use

Chemistry rarely stays on the bench, and 2-Methylpyrrolidine gets proof by use in drug development and specialty chemical production. It serves as a useful intermediate—links in the chain toward active pharmaceutical ingredients or to specialty polymers. Knowing its reactivity and hazard profile pushes companies to rethink traditional batch handling, introducing closed transfer systems and automated dispensing where possible. In workplaces, safety training goes beyond posters—regular drills, real-time air monitoring, and fast access to spill kits set a safer standard than old-school, open-bottle work. At the same time, global trade means shipments cross oceans in bulk UN drums, tracked by material safety codes and handled under international chemical safety requirements. From my experience, investing in good storage and worker protection doesn’t just avoid accidents—it boosts productivity because interruptions and injuries pull everyone off target.

Summary Table: Critical Specifications