4-Methylpyridine, colorless, flammable, volatile liquid. Have an unpleasant sweet taste. The impurity is brown, soluble in water, alcohol and ether. The pharmaceutical industry for the production of drugs and isoniazid, antidote obidoxime and tmb4, also used for pesticides, dyes, rubber chemicals and synthetic resin production.

English Name: 4-Methylpyridine

Nickname: p-methylpyridine

Molecular formula: C₆H₇N

Molecular weight: 93.13

CAS number: 108-89-4

Melting point: 2.4

Boiling point: 144.24 at 760 mmHg

Water solubility; dissolution

Density: 0.941g/cm3

Appearance: colorless liquid

Flash point: 56.67 degrees

Physical and chemical properties

Appearance and properties: colorless, flammable, volatile liquid. Have an unpleasant sweet taste. The impurity is brown.

Molecular formula: C6H7N

Molecular weight: 93.13

Density: 0.941g/cm3

Melting point: 2.4

Boiling point: 144.24 degrees at C 760 mmHg

Flash point: 56.667 ~ C

Vapor pressure: at 6.465mmHg 25 degrees C

Solubility: soluble in water, ethanol and ethyl ether.

The heat of vaporization (KJ/mol, 25 degrees C): 45.35

Melting heat (KJ/mol): 11.58

Generate heat (KJ/mol, liquid): 56.80

The heat of combustion (KJ/mol, 25 degrees C): 3420

The critical temperature (C degrees): 372.5

Critical pressure (KPa): 4.66

The specific heat (KJ/ (kg - K), 25 degrees C, constant pressure): 1.70

PKa:6.02

Expansion coefficient (K-1,25 degrees C): 0.000965

synthetic method

1 by the synthesis process and the production of coal coking by-product recovery. The reaction of acetaldehyde with ammonia, the main production of 2- methyl pyridine and 4- methyl pyridine. The ammonia is preheated to 450 DEG C, and acetaldehyde mixed after gasification, which is provided with aluminum silicate catalyst fluidization reactor is preheated to 430 DEG C, the reaction at 410-430 deg.c, generated by gas separation; condensation reaction liquid, will get into the dewatering pot, solid caustic soda and 2% at 92 DEG C, refluxing 2H. Layering; fractionation, collection of 142-144 C fractions, namely 4- methyl pyridine. Yield of acetaldehyde was 20% (125-130 C fraction was 2- methyl pyridine).

The consumption of raw material: 1174kg/t 3019kg/t liquid ammonia; acetaldehyde.

2 refining methods: the synthesis of the product, almost no 2- methyl pyridine, easy to refine by distillation. The products extracted from coal tar contained 2- methyl pyridine and 2,6- two methyl pyridine. Can be added in the solution of calcium chloride and hydrochloric acid, the resulting adduct crystal with calcium chloride solution after washing with water vapor decomposition, then add salt water treatment to remove the soluble component, and then use the potassium hydroxide solution, oil extraction, 4- methyl pyridine with purity of 99.2%. It can also be made of refined oxalate. For example, the 4- 100mL methyl pyridine heating to 80 degrees, slowly adding 110g anhydrous oxalic acid and 150mL boiling ethanol, after the cold filter, with a small amount of ethanol washing, and then dissolved in a small amount of water, adding excess 50%KOH distillation. The distillate with solid potassium hydroxide after drying and distillation.

purpose

For the production of drugs isoniazid, antidote obidoxime and tmb4, also used in insecticides; dyes; rubber chemicals and synthetic resin production. Used in the preparation of different tobacco acid, hydrazine, pesticide, synthetic resin, rubber vulcanization accelerator, etc.. Can also be used as solvent.