Pyridine

Product Details

CasNo： 110-86-1

MF： 110-86-1

Appearance： liquid

Delivery Time： 15 days

Packing： 200kg/drum

Purity： 99%

1. Basic Information

• Chinese Name: 吡啶 (Synonym: 氮杂苯)
• English Name: Pyridine
• CAS No.: 110-86-1
• Molecular Formula: C₅H₅N
• Molecular Weight: 79.10
• UN Number: 1282 (Hazard Class: Class 3 Flammable Liquids; Packing Group: II)
• Appearance & Odor: Colorless transparent liquid at room temperature, with a strong and pungent characteristic odor (similar to fishy or ammonia-like smell); turns yellow gradually upon long-term storage or exposure to light (due to oxidation-induced impurities).
• Key Physicochemical Parameters:

2. Physical & Chemical Properties

1. Basicity: The nitrogen atom with a lone pair of electrons endows it with weak basicity (pKa ≈ 5.25). It can react with strong acids (e.g., hydrochloric acid, sulfuric acid) to form stable salts (e.g., pyridine hydrochloride) and undergo acylation with acyl chlorides or acid anhydrides. It is a crucial basic catalyst in organic synthesis.
2. Stability & Reactivity: Chemically stable at room temperature but flammable when exposed to open flames or high temperatures (autoignition temperature ≥ 482℃). Combustion releases toxic nitrogen oxides (NOₓ). Under the action of strong oxidants (e.g., potassium permanganate, nitric acid), it can be oxidized to nicotinic acid (pyridine-3-carboxylic acid). With catalysts (e.g., Raney nickel), it can be hydrogenated to hexahydropyridine (piperidine).
3. Corrosiveness: No obvious corrosion to common metals (e.g., iron, copper), but reacts slowly with aluminum upon long-term contact. It swells rubber and plastics, so solvent-resistant materials (e.g., polytetrafluoroethylene, nitrile rubber) should be used for seals.

3. Core Applications

3.1 Pharmaceutical Industry (Primary Application)

• Serves as a pharmaceutical intermediate for synthesizing antibiotics (e.g., side-chain modification of cephalosporins), anti-tuberculosis drugs (isoniazid), antihistamines (chlorpheniramine), and anti-tumor drugs (etoposide).
• Used as a solvent or acid scavenger in pharmaceutical synthesis—for example, neutralizing acids generated during peptide synthesis to promote amide bond formation.

3.2 Pesticide Industry

• Synthesizes high-efficiency pesticides, including insecticides (e.g., imidacloprid, acetamiprid—neonicotinoid pesticides with high selectivity for pests), herbicides (e.g., pyrithiobac-sodium, fluroxypyr), and fungicides (e.g., prochloraz).
• Acts as a solvent in pesticide formulations to improve the solubility and stability of active ingredients and reduce liquid stratification.

3.3 Chemical & Materials Industry

• Produces pyridine derivatives, such as 2-methylpyridine (for vitamin B6 synthesis), 3-methylpyridine (for nicotinic acid synthesis), and 4-methylpyridine (for pharmaceutical intermediates).
• Used as a solvent or modifier in polymer materials—e.g., dissolving polyamides and polyurethanes, and synthesizing heat-resistant resins (e.g., polyimides).
• Functions as a metal extractant for separating precious metals (e.g., platinum, palladium) or rare metals (e.g., neodymium), especially suitable for ion complexation in acidic systems.

3.4 Analytical & Other Fields

• Used as a solvent in chromatographic analysis (e.g., mobile phase additive in high-performance liquid chromatography, HPLC) to adjust the pH of the mobile phase and improve the separation of polar compounds.
• Applied in the rubber industry as a raw material for rubber vulcanization accelerators; in the textile industry, it serves as a dye solvent and fixing agent to enhance dye adhesion to fibers.

4. Quality Specifications (by Grade)

Pyridine is classified into industrial grade and reagent grade (analytical pure/chemical pure) based on purity and application. Key differences in indicators are as follows:

5. Safety, Storage & Transportation Information

5.1 Hazard Warnings

• Toxicity: Moderate toxicity; can enter the human body via inhalation, skin contact, or ingestion. Short-term exposure to high-concentration vapor causes headaches, nausea, tearing, and coughing; long-term exposure may damage the liver and kidneys. Ingestion leads to oral and esophageal burns, and even central nervous system depression.
• Irritation: Vapor strongly irritates the eyes and mucous membranes (e.g., nasal cavity, respiratory tract); liquid contact causes skin redness and burns.
• Flammability: With a flash point of 20℃, it easily ignites upon contact with open flames or electrostatic sparks (e.g., ungrounded equipment). Combustion releases toxic NOₓ gas; smoking or using non-explosion-proof equipment in work areas is strictly prohibited.

5.2 Storage Requirements

• Store in a cool, well-ventilated, explosion-proof warehouse at a temperature not exceeding 30℃. Keep away from ignition sources and heat (e.g., radiators, heaters) and avoid direct sunlight (to prevent discoloration and purity loss).
• Use solvent-resistant glass bottles (for reagent grade) or steel drums (for industrial grade, with inner anti-corrosion coating) as containers. Ensure tight sealing to prevent volatilization.
• Store strictly separately from strong acids (e.g., hydrochloric acid, sulfuric acid), strong oxidants (e.g., potassium permanganate, hydrogen peroxide), and food chemicals to avoid reactions (e.g., salt formation with strong acids, causing drum rupture).
• Equip the storage area with dry powder fire extinguishers and foam fire extinguishers (water extinguishing is prohibited—pyridine is insoluble in water and less dense, so pouring water spreads the fire). Post "Flammable & Toxic" and "No Open Flames" warning signs, and install eye wash stations and emergency showers.

5.3 Transportation Specifications

• Regulated as a hazardous chemical with UN Number: 1282, Hazard Class: Class 3 Flammable Liquids, Packing Group: II.
• Transport vehicles must have explosion-proof qualifications and be equipped with anti-static grounding devices; mixed loading with other hazardous materials is prohibited.
• Avoid severe collisions, exposure to sunlight, or rain during transportation. In summer, transport in the morning and evening to avoid high-temperature periods. Handle with care during loading/unloading to prevent container damage and leakage.

6. Environmental Characteristics

• Pyridine degrades slowly in nature (taking months to years), but large-scale leakage pollutes soil and water bodies, causing aquatic organism death. Leaked pyridine should be promptly absorbed with adsorbents (e.g., activated carbon, diatomaceous earth); direct discharge into sewers or rivers is strictly prohibited.
• Industrial wastewater must undergo pre-treatment (e.g., advanced oxidation, biodegradation to remove pyridine) and meet the Integrated Wastewater Discharge Standard (GB 8978-1996) before discharge.
• Waste pyridine must be incinerated by qualified units. Incineration facilities should be equipped with exhaust gas purification devices to remove NOₓ and unburned pyridine vapor, preventing air pollution.