General Description
Colorless moderately volatile liquid.
Reactivity Profile
4-METHYL PYRIDINE(108-89-4) neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen may be generated in combination with strong reducing agents, such as hydrides.
Air & Water Reactions
Highly flammable.
Health Hazard
ACUTE/CHRONIC HAZARDS: Moderate fire risk.
Potential Exposure
(o-isomer); Suspected reprotoxic hazard, Primary irritant (w/o allergic reaction), (m-isomer): Possible risk of forming tumors, Primary irritant (w/o allergic reaction). Picolines are used as intermediates in pharmaceutical manufacture, pesticide manufacture; and in the manufacture of dyes and rubber chemicals. It is also used as a solvent.
Fire Hazard
HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
First aid
If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Speed in removing material from skin is of extreme importance. Shampoo hair promptly if contaminated. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit.
Shipping
UN2313 Picolines, Hazard Class: 3; Labels: 3-Flammable liquid.
Incompatibilities
Vapors may form explosive mixture with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Attacks copper and its alloys.
Chemical Properties
4-Methylpyridine is a Colorless to light yellow liquid with an obnoxious, sweetish odor.
Occurrence
4-Methylpyridine is released by energy-related processes. It is present in coal gassification wastewater (Pellizzari et al 1979), the environment of coke ovens (Naizer and Mashek 1974) and in waters from shale oil waste production (Dobson et al 1985; Hawthorne et al 1985; Leenheer et al 1982). It is also present in coal tar (HSDB, 1988), cigarette smoke (Brunneman et al 1978; IARC 1976) and pyroligneous liquids from woods (Yasuhara and Sugiwara 1987). Methods for the biological treatment of wastewaters containing 4-methylpyridine have been developed (Roubickova 1986) and its movement through (Leenheer and Stuber 1981) and degradation (Sims and Somners 1985) in soils examined.
Uses
4-Methylpyridine was used in the preparation of a 1,2-dihydropyridide derivative.
Uses
4-Methylpyridine is used to manufacture isonicotinic
acid and derivatives, in waterproofing agents for fabric,
and as a solvent for resins, pharmaceuticals, dyestuffs,
rubber accelerators, and pesticides. It is also used as a catalyst
and curing agent.
Definition
ChEBI: 4-methylpyridine is a methylpyridine in which the methyl substituent is at position 4.
Production Methods
Currently, 4-methylpyridine is produced by vapor-phase condensation of acetaldehyde and ammonia (3:1) with subsequent isolation of 4-methylpyridine from the reaction mixture. Reactants are exposed to dehydration-dehydrogenation catalysis such as lead oxide, copper oxide on alumina, thorium oxide, zinc oxide or cadmium oxide on silica-alumina, or cadmium fluoride on silica-magnesia at 400-500°C. This results in a 60% yield of 4-methylpyridine which is isolated by fractional distillation (USEPA 1982). Another production method involves the isolation from by-products of coking operations. The crude pyridine extracts come from noncondensable and condensable coke-oven gasses that have been dehydrated and separated by fractional distillation, but only 45% of 4-methylpyridine is obtained (USEPA 1982). 4-Methylpyridine also can be isolated from a dry distillation of bones or coal (Hawley 1977).
Flammability and Explosibility
Flammable
Industrial uses
4-Methylpyridine is used as a water-proofing agent for fabrics; as solvents for resins; in the synthesis of pharmaceuticals, dyestuffs, rubber accelerators, pesticides and laboratory reagent; as a catalyst; and as a curing agent (Hawley 1977; Windholz et al 1983). It is used for the synthesis of pharmaceuticals, especially isoniazid (USEPA 1982) and also for the production of 4-vinylpyridine to improve dyeability (USEPA 1982).
Purification Methods
It can be purified as for 2-methylpyridine. Biddescombe and Handley's method (above) for 3-methylpyridine is also applicable. Lidstone [J Chem Soc 242 1940] purified it via the oxalate (m 137-138o) by heating 100mL of 4-methylpyridine to 80o and adding slowly110g of anhydrous oxalic acid, followed by 150mL of boiling EtOH. After cooling and filtering, the precipitate is washed with a little EtOH, then recrystallised from EtOH, dissolved in the minimum quantity of water and distilled with excess 50% KOH. The distillate is dried with solid KOH and again distilled. Hydrocarbons can be removed from 4-methylpyridine by converting the latter to its hydrochloride, crystallising from EtOH/diethyl ether, regenerating the free base by adding alkali and distilling. As a final purification step, 4-methylpyridine can be fractionally crystallised by partial freezing to effect a separation from 3-methylpyridine. Contamination with 2,6-lutidine is detected by its strong absorption at 270nm. The hydrochloride has m 161o, and the picrate has m 167o(from Me2CO, EtOH or H2O). [Beilstein 20 III/IV 2732, 20/5 V 543.]