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Introduction Application Analysis of demand in pesticides Toxicity Hazards Physical and chemical properties Preparation Category Toxic grading Acute toxicity Stimulate data Explosive hazardous characteristics Flammability hazard characteristics Storage characteristics Extinguishing agent

CAS No.110-86-1
Chemical Name:Pyridine
Synonyms:AA;PY;PYR;cp32;Azine;Pirydyna;Piridina;PYRIDINE;ai3-01240;FEMA 2932
Molecular Formula:C5H5N
Formula Weight:79.1
MOL File:110-86-1.mol
Pyridine Property
Melting point : -42 °C
Boiling point : 96-98 °C(lit.)
density : 0.983 g/mL at 20 °C
vapor density : 2.72 (vs air)
vapor pressure : 23.8 mm Hg ( 25 °C)
refractive index : n20/D 1.509(lit.)
FEMA : 2966
Fp : 68 °F
storage temp. : Store at RT.
Water Solubility : Miscible
FreezingPoint : -42℃
Merck : 14,7970
BRN : 103233
Stability:: Stable. Flammable. Incompatible with strong oxidizing agents, strong acids.
CAS DataBase Reference: 110-86-1(CAS DataBase Reference)
NIST Chemistry Reference: Pyridine(110-86-1)
EPA Substance Registry System: Pyridine(110-86-1)
Hazard Codes : T,N,F,Xn
Risk Statements : 11-20/21/22-39/23/24/25-23/24/25-52-36/38
Safety Statements : 36/37/39-38-45-61-28A-26-28-24/25-22-36/37-16-7
RIDADR : UN 1282 3/PG 2
WGK Germany : 2
RTECS : UR8400000
F : 3-10
Hazard Note : Highly Flammable/Harmful
HazardClass : 3
PackingGroup : II
Hazardous Substances Data: 110-86-1(Hazardous Substances Data)

Pyridine Chemical Properties,Usage,Production

Pyridine (Formula is C6H5N) is a six-membered heterocyclic compound containing one nitrogen heteroatom. It is structurally related to benzene, with one methine group (=CH−) replaced by a nitrogen atom. Just like benzene, Pyridine has same electronic structure, and it is still aromatic, so it is also known as nitrogen benzene and azobenzene. Pyridine is a colorless liquid with special odor at room temperature, and melting point is -41.6 ℃, and boiling point is 115.2 ℃. It will form azeotropic mixture with water, and boiling point of the mixture is 92 ~ 93 ℃(The property is used to purify pyridine in industry.) Its density is 0.9819g / cm3. Pyridine is soluble in water, ethanol, ether and other organic solvents, and itself can also be used as solvent. Pyridine was discovered in 1849 by the Scottish chemist Thomas Anderson as one of the constituents of bone oil. Two years later, Anderson isolated pure pyridine through fractional distillation of the oil.
Pyridine and its derivatives are more stable than benzene, and their reactivity is similar to that of nitrobenzene. Due to the electron absorption of nitrogen atom in the ring, the electron density at the 2,4,6 position is lower than 3 and 5, and the typical aromatic electrophilic substitution reaction occurs at 3 and 5, but the reactivity is lower than that of benzene, generally less prone to nitration, halogenation, sulfonation and other reactions. In addition, these substitution reactions are carried out in an acidic medium, and pyridine forms positively charged ion, making the electrophilic reagent difficult to approach. 2- or 4-halopyridine halogens are active. Since the electron density at the 2 and 6 positions is low, nucleophilic substitution reaction can occur at the position, such as reaction with sodium amide or potassium hydroxide to give the corresponding 2-aminopyridine or 2-hydroxypyridine.
Pyridine can also be used as denaturant, auxiliaries and as a starting material for the synthesis of a range of products, including pharmaceuticals, disinfectants, dyes, food seasonings, binders, explosives and so on. Pyridine is toxic, and its inhalation, ingestion or skin contact can lead to reduced male fertility, and It is also carcinogenic.
Pyridine is a weak tertiary amine, forming water-insoluble salt with a variety of acids (such as picric acid or perchloric acid, etc.) in the ethanol. There is about 1% 2-methylpyridine in pyridine that is used industrially, so that it can be separated from its homologues by using the difference in salt form properties. Pyridine also forms a crystalline complex with a variety of metal ions.
Pyridine is easier to reduce than benzene. For example, Pyridine is reduced to hexahydropyridine (or piperidine) with the metal sodium and ethanol. Pyridine could react with hydrogen peroxide, and easily be oxidized to N-oxide pyridine. N-oxide pyridine is an important pyridine derivative. Because the nitrogen atom is oxidized, it cannot form a positively charged pyridine ion, which is conducive to the occurrence of aromatic electrophilic substitution reaction. After the replacement, the oxygen atom on the nitrogen is removed, so it is possible to obtain a derivative which cannot be directly substituted by pyridine.
Structurally, pyridine is a heterocyclic compound, in which a nitrogen atom replaces a carbon atom on benzene. One of the five electrons of the nitrogen atom is used to form large Π bonds with other carbon atoms, so that the other two are localized lone-pairs, so pyridine is basic and is a good ligand (the ligand is written as py). Its conjugate acid ion of pyridine has a PKa value of 5.30.
Methods of purification and dewatering
Analytical pure pyridine contains a small amount of water, and it is used for general experiments. To prepare anhydrous pyridine, pyridine can be refluxed with potassium hydroxide (sodium) and then removed from moisture. Dry pyridine absorbs water strongly, so the container should be sealed with paraffin.
Source and synthesis method
Pyridine can be extracted from coke gas and tar. The coking gas is passed through sulfuric acid to absorb nitrogenous basic substances such as ammonia and pyridine, and the resulting ammonium sulfate salts are treated with ammonia to separate the free nitrogen-containing organic bases and then distilled to obtain the mixture of pyridine and its alkyl substituent. Pyridine can also be prepared from acetaldehyde and ammonia. Pyridine and its derivatives can be synthesized by a variety of methods. One of the most widely used is the Hanqi pyridine synthesis method. The process is as follows: two molecules of β-carbonyl compounds, such as ethyl acetoacetate, and one molecular acetaldehyde condensate, and the product condensates with one molecular ethyl acetoacetate and ammonia to form dihydropyridine compounds, and then dehydrogenate with oxidizing agent (such as nitrous acid )and hydrolyze to remove carboxyl, finally pyridine derivatives are prepared. Pyridine can also be prepared using acetylene, ammonia and methanol under catalytic conditions at 500 ° C.
Among the many derivatives of pyridine, some are important drugs, and some are important components of vitamins or enzymes. For example, pyridine-3-carboxylic acid amide (i.e., nicotinamide) forms an important dinucleotide in coenzyme I with adenine (see purine), ribose and phosphoric acid. Isoniazid, one of derivatives of pyridine, is an oral anti-tuberculosis drug. 2-methyl-5-vinylpyridine is an important raw material for rubber synthesis. Pyridine can be obtained from natural coal tar and can also be prepared from acetaldehyde and ammonia. In addition to solvents, pyridine can also be used as denaturant, auxiliaries, and a starting material for the synthesis of a range of products, including pharmaceuticals, disinfectants, dyes, food seasonings, binders, explosives and so on.
Related information for downstream products:
Precursor to agrochemicals and pharmaceuticals: Herbicides (paraquat, diquat and picloram): clear field weeds and control aquatic weeds; Insecticide (chlorpyrifos, chlorpyrifos-methyl and esbiothrin): broad spectrum insecticide, efficient, low toxicity home hygiene insecticide
Pyrithione: zinc pyrithione or 2-mercaptopyridine-N-oxide zinc salt, sodium pyrithione (application: broad-spectrum antimicrobial agents. It could kill Gram (negative, positive) bacteria and fungi, and it is an active agent of dandruff shampoo that is common used internationally; Zinc pyrithione can be incorporated into carpet adhesives to inhibit bacterial growth; Potassium pyrithione can be incorporated into metalworking fluids for antifungal growth.)
Synthesis of quaternary salt: Cetylpyridinium chloride (production for mouthwash, hair conditioner regulator, phase transfer catalyst)
New polymer compounds: poly 4- (3-pyrrolinyl) pyridine (with highly efficient acylation catalyst groups)
Piperidine: Bis-piperidinyl dicumyl tetrasulfide (rubber hardening accelerator), N, N-dimethylpiperidinium chloride (plant growth regulator), Epoxy curing agent, group protection agent, special solvent.
Dyes: Blue base BB, blue base RR, disperse blue S-RB, soluble reducing ash IBL, soluble reduced blue IBC, etc.
Pharmaceutical intermediates: solvents for cephalosporins, steroids, sulfonamide; absorb chlorine for antihistamines and antidote; In the case of penicillin, pentadecyl bromide is used as a precipitant for the protein; demulsifier for extraction of chlortetracycline; A 1-nucleophilic reaction of 2-chloropyridine produces an amide blocker; phenriamine, bromoaniline maleate, chloroaniline maleate; diosocalamide (treatment of arrhythmia)
The rest: dodecylpyridinium chloride (laurylpyridinium chloride); Pyridine is a precursor of various derivatives (such as pyridine-N-oxide, pyridinium perchloride, phenylpyridinium chloride, halogenated, aminopyridine, etc.).
For the manufacture of vitamins, sulfonamides, pesticides and plastics; as solvent; as a denaturant, auxiliaries, and a starting material for the synthesis of a range of products ,including pharmaceuticals, disinfectants, dyes, food seasonings, binders, explosives and so on.
Analysis of demand in pesticides
As the world's fourth generation of new pesticides, the advantages of pyridine pesticides are obvious. Pyridine-containing pesticides are not only efficient, low toxic and long lasting, it also has good environmental compatibility for humans and organisms, in line with the development requirements and trends of pesticides. In recent years, pyridine-containing pesticide developed rapidly, covering pesticides, herbicides, fungicides, and it has become one of the main direction of pesticide creation. The pyridine compounds were initially extracted from coal tar. With the growth of China's economy on the market demand for pyridine compounds and the development of pyridine compounds synthesis technology, the production, consumption and exports of China's pyridine compounds accounted for 30% of the world's pyridine compounds. Pyridine compounds are mainly used in the production of herbicides paraquat and durum fast, nicotinic acid and nicotinamide, and pesticide intermediates. The application is very extensive, and deep processing prospects are quite broad, so it is one of fine chemicals with urgent need to develop.
In 2007, China's imports of pyridine compounds were 16750 tons, mainly from India (49.49%), the United States (19.74%), China Taiwan (19.58%), Japan (8.99%), of which pure pyridine imports accounted for 95.2% of total imports.
In 2007, pyridine compounds were mainly used for agricultural chemicals, accounting for 52% (90% of paraquat); 40% of pharmaceutical intermediates / feed additives (60% of nicotinamide / nicotinic acid); SBV (benzene Ethylene-butadiene-2-vinyl pyridine) latex accounts for 3.5%; other (household chemicals, coatings and other intermediates) accounts for 4.5%. The growth rate of main varieties of pyridine pesticide is expected to more than 15% in next three years, beyond the industry average. In the context of the global economic slowdown, pesticides are less affected by the macroeconomic than ordinary chemical product, and we expect the global pesticide consumption in 2009 increased by 5-10%. It is expected that the growth rate of global pyridine base (pyridine and series derivatives) will be about 20% in the next three years, while the demand for paraquat, chlorpyrifos and imidacloprid in the main pyridine pesticide varieties is expected to be more than 15%, exceeding the industry average.
From the perspective of industry chain of pyridine compounds, technology barriers to synthesize pyridine base through formaldehyde, acetaldehyde, ammonia and other major raw materials still exist. As representative, Swiss Long Sha and the United States’ Rayleigh monopolize the market in the global scope, which is the main reason for the high prices of pyridine downstream compounds.
As spice, it can be used in food safely (FDA, § 172.515, 2000).
FEMA (mg/kg): Soft drink 1.0; mouth drink 0.02 ~ 0.12; candy and baked goods 0.4.
Invasive approach: inhalation, ingestion, percutaneous absorption.
Health hazards: strong irritation; anesthetize central nervous system; irritation for eye and upper respiratory tract. If high concentration of inhalation, the light were euphoric or has a choking feeling, followed by depression, muscle weakness, vomiting; the severe with loss of consciousness, incontinence, a tonic spasm and depressed blood pressure.
Chronic effects: Long-term inhalation leads to dizziness, headache, insomnia, gait instability and gastrointestinal dysfunction. It could damage liver and kidney. And it causes dermatitis.
Acute toxicity: LD501580mg / kg (rat oral); 1121mg / kg (rabbit skin); human inhalation 25mg / m3 × 20 minutes, irritation for conjunctiva and upper respiratory tract.
Subacute and chronic toxicity: Inhalation of rats 32.3mg / m3 × 7 hours / day × 5 days / week × 6 months, weight coefficient of liver increases; people inhalation 20 ~ 40mg / m3 (long), mental decline, gait instability, finger tremor, low blood pressure, sweating, liver and kidney damage for individual.
Physical and chemical properties
It is a colorless or light yellow liquid with nasty smell, and it is soluble in water, ethanol, acetone, ether and benzene.
Pyridine was previously extracted from coal tar. Coke oven gas was washed with sulfuric acid, and ammonia was used to neutralize to obtain crude light pyridine, and then purified by distillation. With the expansion of application, synthesis method of pyridine has a greater development. Pyridine and pyridyl compounds obtained from coal tar are 10% abroad. A mixture of acetaldehyde (1.648 mol), 37% formaldehyde (1.665 mol) and ammonia (3.096 mol) was reacted at 432 ° C. The catalyst was SiO2-Al2O3-Bi2O3, and the yield of pyridine was 48.4%, and produce β-methylpyridine. If changing the operating conditions, the yield of pyridine and picoline could be adjusted. In addition, 1,5-pentanediamine hydrochloride can also be used to obtain pyridine by heating cyclization and dehydrogenation in the presence of Pt catalyst.
The saturated mother liquor after high temperature coking is used as raw material, then recover and process to obtain crude pyridine and heat and slag to obtain water- containing pyridine. After constant boiling with pure benzene to dehydrate to obtain anhydrous pyridine, and then distillate to obtain 110 ~ 120 ℃ fractions, and finally distillate.
Flammable liquid
Toxic grading
Moderate toxicity
Acute toxicity
Oral-rat LD50: 891 mg / kg; intravenous-mouse LD50: 1500 mg / kg
Stimulate data
Eyes - rabbit 2 mg severe; skin - rabbit 10 mg / 24 hours mild
Explosive hazardous characteristics
Explode mixed with air
Flammability hazard characteristics
It is flammable in case of fire, high temperature and oxidant, and produce toxic nitrogen oxide smoke.
Storage characteristics
Ventilated warehouse, low temperature, dry; separate storage with oxidants and acid
Extinguishing agent
Dry powder, dry sand, carbon dioxide, foam, 1211 fire extinguishing agent.
Chemical Properties
Colorless to light yellow liquid
General Description
A clear colorless to light yellow liquid with a penetrating nauseating odor. Density 0.978 g / cm3. Flash point 68°F. Vapors are heavier than air. Toxic by ingestion and inhalation. Combustion produces toxic oxides of nitrogen.
Air & Water Reactions
Highly flammable. Soluble in water.
Reactivity Profile
Azabenzene is a base. Reacts exothermically with acids. During preparation of a complex of Azabenzene with chromium trioxide, an acid, the proportion of chromium trioxide was increased. Heating from this acid-base reaction led to an explosion and fire [MCA Case History 1284 1967]. A 0.1% solution of Azabenzene (or other tertiary amine) in maleic anhydride at 185°C gives an exothermic decomposition with rapid evolution of gas [Chem Eng. News 42(8); 41 1964]. Mixing Azabenzene in equal molar portions with any of the following substances in a closed container caused the temperature and pressure to increase: chlorosulfonic acid, nitric acid (70%), oleum, sulfuric acid (96%), or propiolactone [NFPA 1991]. The combination of iodine, Azabenzene, sulfur trioxide, and formamide developed a gas over pressurization after several months. This arose from the slow formation of sulfuric acid from external water, or from dehydration of the formamide to hydrogen cyanide. Ethylene oxide and SO2 can react violently in Azabenzene solution with pressurization if ethylene oxide is in excess (Nolan, 1983, Case History 51).
Health Hazard
Vapor irritates eyes and nose. Liquid irritates skin and is absorbed through the skin. Overexposure causes nausea, headache, nervous symptoms, increased urinary frequency.
Fire Hazard
Behavior in Fire: Vapor is heavier than air and may travel considerable distance to source of ignition and flash back.
Pyridine Preparation Products And Raw materials
Raw materials
Preparation Products
4-BROMO-TETRAHYDROPYRAN N-PHENYLISONICOTINAMIDE 2-AMINO-6-CHLORO-3,5-DICYANOPYRIDINE Pyridinium toluene-4-sulphonate Paraquat dichloride 1-CHLORO-2-METHYLPROPYL CHLOROFORMATE 1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one Pyrazinecarbonitrile 7-ACETOXYCOUMARIN Phenylcarbamic acid propyl ester 2-Amino-4-methyl-5-acetylthiazole 5-ACETAMIDONICOTINIC ACID Benzyl 2-chloroacetate trans-Ferulic acid 2-AMINO-4-METHYL-QUINOLINE-3-CARBONITRILE 3-(Trifluoromethyl)pyrazole 3-(TRIFLUOROMETHOXY)CINNAMIC ACID 1-Phenacylpyridinium bromide (4-FLUORO-BENZYL)-METHYL-AMINE 5-METHYLPICOLINIC ACID Indigosol Green Blue IBC 2,4-MESITYLENEDISULFONYL DICHLORIDE 17beta-Hydroxy-17-methylandrosta-4,9(11)-dien-3-one 2-(2-Butoxyethoxy)ethyl acetate Allyl methyl carbonate 3,5-DIMETHOXYCINNAMIC ACID 4-Acetamido-2-chloropyridine 4-Fluorocinnamic acid Hydrocortisone acetate Methyl 2-Fluoroisonicotinate 2-ACETYL-5-CYANOTHIOPHENE 5-BROMO-2-FLUOROCINNAMIC ACID 4-NITROISOPHTHALIC ACID 3,5-Dimethoxy-4-hydroxybenzaldehyde 2,4,5,6-TETRAMETHYLBENZENEDISULFONYL DICHLORIDE PYRIDINE-3-SULFONYL CHLORIDE 3-Methoxycinnamic acid butyl N-phenylcarbamate 3-(3-METHYL-2-THIENYL)ACRYLIC ACID Vat Grey M
Pyridine Suppliers      Global( 330)Suppliers     
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110-86-1(Pyridine)Related Search:
Bathophenanthroline 3,4,7,8-Tetramethyl-1,10-phenanthroline 4,7-Dimethyl-1,10-phenanthroline BATHOPHENANTHROLINEDISULFONIC ACID DISODIUM SALT TRIHYDRATE 4,7-PHENANTHROLINE peroxyacetyl nitrate 5-Nitro-1,10-phenanthroline BANISTERINE MONOHYDRATE 4,5-DIHYDRO-3-(4-PYRIDINYL)-2H-BENZ(G)-INDAZOLE, 99 METHYL 2-BROMO-5-FLUOROISONICOTINATE 5-CHLORO-1,10-PHENANTHROLINE Pyridine 1,7-PHENANTHROLINE 7,8-BENZOQUINOLINE Neocuproine Bathocuproin 4-METHYL-1,10-PHENANTHROLINE 2-Bromo-5-fluoroisonicotinic acid
ai3-01240 Azine cp32 NCI-C55301 Piridina Pirydyna Pyridin(1.Modifikation) pyridinecarboxylicacid,2-(4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1h-imidazol-2-yl)-5-methyl pyridinecarboxylicacid,2-(4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1h-imidazol-2-yl)-5-methyl,monoammoniumsalt Rcra waste number U196 rcrawastenumberu196 FEMA 2932 FEMA 2966 FEMA NUMBER 2966 azabenzene 110-86-1 Alkenes Acyclic Building Blocks 2-PROPENOL 2-Propen-1-c 2-PROPENE-1-OL AA ALLYL ALCOHOL, POLYMER-BOUND AKOS BBS-00004376 Organic Building Blocks PYRIDINE PY PYR PYRIDINE FRACTION Pyridine anhydrous Pyridine 1 Degree Pyridine ACS grade Pyridine pharma grade PYRIDINE, FOR UV-SPECTROSCOPY PYRIDINE, REAGENTPLUS, >=99% PYRIDINE, 99+%, SPECTROPHOTOMETRIC GRADE PYRIDINE, ABSOLUTE, OVER MOLECULAR SIEVE (H2O <0.005%) PYRIDINE, ANHYDROUS, 99.8% PYRIDINE, ACS REAGENT, >=99.0% PYRIDINE 99+% A.C.S. REAGENT (POLY- & PYRIDINE, BIOTECH GRADE SOLVENT, 99.9+% PYRIDINE, DIST., 1 L PYRIDINE PURIFICATION GRADE >=99.75% PYRIDINE CHROMASOLV FOR HPLC >=99.9% PYRIDINE, 99+%, A.C.S. REAGENT PYRIDINE, STANDARD FOR GC PYRIDINE EXTRA PURE PYRIDINE R. G., REAG. ACS, REAG. PH.EUR. PYRIDINE DRIED (MAX. 0,0075 % H2O), R. G ., REAG. PH. EUR. PYRIDINE MIN 99.7% PYRIDINE ACS REAGENT PYRIDINE, FOR PROTEIN SEQUENCE ANALYSIS PYRIDINE, 99+%, A.C.S. REAGENT (SAFETY C AN) PYRIDINE 99+% A.C.S. REAGENT (SAFETY & PYRIDINE, 99.9+%, HPLC GRADE PYRIDINE 99+% PYRIDINE, 4X25 ML
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