Glyoxal

Glyoxal - Names and Identifiers

Name	Glyoxal
Synonyms	Glyoxal ethanedial 1,2-Ethanedione Glyoxal solution
CAS	107-22-2
EINECS	203-474-9
InChI	InChI=1/C2H2O2/c3-1-2-4/h1-2H
InChIKey	LEQAOMBKQFMDFZ-UHFFFAOYSA-N

Glyoxal - Physico-chemical Properties

Molecular Formula	C2H2O2
Molar Mass	58.0361
Density	1.032g/cm³
Melting Point	-14℃
Boling Point	50°C at 760 mmHg
Flash Point	104°C
Water Solubility	miscible
Solubility	water: soluble(lit.)
Vapor Presure	292mmHg at 25°C
Vapor Density	>1 (vs air)
Appearance	Liquid
Color	Clear colorless to yellow
Exposure Limit	ACGIH: TWA 0.1 mg/m3
Merck	14,4509
BRN	1732463
Storage Condition	2-8°C
Stability	Stability Combustible. Incompatible with strong oxidizing agents. Strong reducing agent. May polyermize exothermically. Incompatible with air, water, oxygen, peroxides, amides, amines, hydroxy-contain
Refractive Index	1.337
Physical and Chemical Properties	Characteristics of colorless or light yellow prismatic crystals or liquid, the crystallization of easy deliquescence. The vapor is green, with a purple flame when burned. melting point 15 ℃ boiling point 50.5 ℃ relative density 1.14g/cm3 refractive index 1.3826 solubility soluble in water, soluble in common organic solvents.
Use	Used as pharmaceutical intermediates, fabric finishing agents, dyes and dye intermediates

Glyoxal - Risk and Safety

Hazard Symbols	Xn - Harmful
Risk Codes	R20 - Harmful by inhalation R36/38 - Irritating to eyes and skin. R43 - May cause sensitization by skin contact R68 - Possible risk of irreversible effects
Safety Description	S36/37 - Wear suitable protective clothing and gloves.
UN IDs	UN 1760
WGK Germany	1
RTECS	MD2700000
TSCA	Yes
Autoignition Temperature	545 °F
HS Code	29121900
Toxicity	LD50 in rats, guinea pigs (mg/kg): 2020, 760 orally (Smyth)

Glyoxal - Upstream Downstream Industry

Raw Materials	Methyl alcohol Ethylene glycol
Downstream Products	4-Hydroxyphenylacetic acid D(-)-4-Hydroxyphenylglycine Glyoxylic acid 4-Hydroxybenzeneacetamide 2-Methylimidazole Imidazole 2,6-Dichloropyrazine 2-Chloropyrazine 2-Methyl-5-nitroimidazole-1-ethanol amiloride hydrochloride hydrate 2-Isobutyl-3-methoxypyrazine 2-Isopropyl-3-methoxypyrazine 2-Ethylpyrazine

Glyoxal - Nature

Open Data Verified Data

yellow crystals. d20 1.14; Melting point 15 ℃, boiling point 51 ℃ I refractive index 1. 3826. Soluble in water, soluble in alcohol and ether. Unstable, so the general use of 40% ~ 41% concentration of aqueous solution, the solution is colorless light yellow transparent liquid, relative density of 1. 260~310. With strong reduction. Exposure to air can cause an explosion. A strong polymerization reaction occurs in contact with water. It reacts strongly with chlorosulfonic acid, ethylene imine, nitric acid, fuming sulfuric acid and sodium hydroxide. Toxic, irritating smoke is emitted during combustion.

Last Update：2024-01-02 23:10:35

Glyoxal - Preparation Method

Open Data Verified Data

using copper nitrate as a catalyst, acetaldehyde was obtained by liquid phase oxidation with nitric acid. Or the use of silver or phosphor bronze and its oxide as the main catalyst, phosphorus compounds as co-catalyst, ethylene glycol by air catalytic oxidation (gas phase) to obtain crude ethylene glycol; And then by ion resin exchange treatment, activated carbon can be concentrated After decolorization.

Last Update：2022-01-01 09:28:03

Glyoxal - Use

Open Data Verified Data

It can be used as a bactericide for water-based oil well fracturing fluid, a crosslinking agent for cellulose, etc. In the textile printing and dyeing industry, it is used as an anti-shrinkage and anti-wrinkle finishing agent for fabrics. In the leather industry, the primer of glyoxal and isobutyraldehyde semicarbazide can be used as a tanning agent for leather, glyoxal and amine condensation to produce 2 hydroxypyrazine, as raw materials of sulfonamides and pesticides. In coatings and adhesives, cross-linking with the polymer may improve the water resistance of the copolymer. Acrylamide copolymer and glyoxal cross-linking, can be used as glass fiber board.

Last Update：2022-01-01 09:28:04

Glyoxal - Safety

Open Data Verified Data

rat oral LD50: 2020mg/kg; Mouse oral LD50 is 600-lo00 mg/kg (based on 100% glyoxal). Strong irritation of skin and mucosa. Inhalation, ingestion or absorption through the skin may be harmful to the human body. Its vapour or smoke is irritating to the eyes, skin, mucous membranes and upper respiratory tract. Store in a cool, ventilated warehouse. Keep away from fire and heat source. Packaging is required to be sealed and not to be in contact with air. Should not be stored for a long time to avoid deterioration. Should be stored separately from alkali, acid, wet items, etc.

Last Update：2022-01-01 09:28:04

Glyoxal - Additional information

Introduction Glyoxal is an organic compound with the chemical formula OCHCHO, which is connected by two aldehyde groups-C = O-H. It is the simplest dialdehyde and is a yellow liquid at room temperature.
Application
The applications of glyoxal are: used as solubilizer and crosslinking agent in polymer chemistry; used in organic synthesis, especially when constructing heterocyclic rings such as imidazole.

In the preparation industry, glyoxal can be prepared by the gas phase oxidation of ethylene glycol under the catalysis of silver or copper, or the oxidation of acetaldehyde with nitric acid solution. In the laboratory, glyoxal is prepared by oxidizing acetaldehyde with selenite. Anhydrous glyoxal can be prepared by co-heating solid hydrate with phosphorus pentoxide.
Chemical properties colorless or light yellow prismatic crystals or liquids, crystals are easy to deliquesce. The vapor is green and has a purple flame when burned. Soluble in water, easily soluble in common organic solvents.
Used as viscose fiber finishing agent, insoluble binder of polyvinyl alcohol, starch, etc., and raw materials for paint, dye and medicine
Used as pharmaceutical intermediates, fabric finishing agents, dyes and dye intermediates
Use glyoxal is the raw material for preparing imidazole. Imidazole is an intermediate of fungicides imidazole, prochloraz, etc. In addition, glyoxal is mainly used in medicine, textiles, building materials, papermaking, daily chemicals, coatings and bonding materials, etc., and can be used as dye intermediates.
Uses Glyoxal is mainly used in the textile industry. As a fiber treatment agent, it can increase the spinning and wrinkle resistance of cotton, nylon and other fibers. It is a durable pressing finishing agent. This use accounts for 80% of the total glyoxal consumption in Japan. Acetaldehyde is an insoluble binder such as gelatin, animal gum, cheese, polyvinyl alcohol and starch. Glyoxal is also used in the leather industry and the production of waterproof matches. Glyoxal is a raw material for organic synthesis. Acetaldehyde, urea, and formaldehyde are heated and condensed in the presence of sodium carbonate to obtain a 2D-resin, which is used as a fabric finishing agent; glyoxal reacts with formaldehyde and ammonium sulfate to synthesize imidazole, and then synthesize imidazole antifungal drugs Clotrimazole, miconazole, etc.; glyoxal and o-phenylenediamine cyclize to obtain benzopyrazine: it is an intermediate of the anti-tuberculosis drug pyrazinamide. Hydroxyphenylacetic acid, produced from glyoxal, has been produced industrially in Japan for use as an intermediate in the antimicrobial and vitamin A series products. Glyoxal is also used in the synthesis of berberine hydrochloride and sulfamethoxypyrazine. It is also used for insecticide, deodorant, corpse preservative, sand curing agent.
Uses Used as a shrinkage inhibitor for adhesives and rayon, and also used in organic synthesis
Use gelatin, animal glue, cheese and other insoluble adhesive, rayon shrink agent, organic synthesis. Mainly used in medicine, textiles, building materials, papermaking, daily chemicals, coatings and bonding materials, etc.
Production methods The main industrial production methods are ethylene glycol gas phase catalytic oxidation and acetaldehyde nitric acid oxidation. 1. Glyoxal phase catalytic oxidation method Ethylene glycol and air are catalyzed and oxidized at 250-300 ℃ in the presence of copper catalyst to generate glyoxal: the active component of the catalyst is copper oxide (containing Cu03-8%), and the carrier is alumina or corundum, aluminum sand, and copper nitrate is impregnated and roasted. The service life is up to one year, and it is regenerated by burning. After preheating and gasification of ethylene glycol, it is mixed with circulating gas and enters the catalytic reactor to control the amount of fresh air to prevent the deep oxidation of ethylene glycol, and the halogen compound is brought into the nitrogen stream as an inhibitor of the deep oxidation. The reaction is carried out at 275 ℃,0.74MPa pressure, the reaction product is cooled with water, and the concentration obtained by absorption is the finished product. The conversion rate of ethylene glycol plus one pass is 80-85%. 2. Acetaldehyde nitric acid oxidation method uses copper nitrate as catalyst and nitric acid for liquid phase oxidation: under the conditions of stirring and full cooling, acetaldehyde and nitric acid are respectively prepared into a solution of about 50%, copper nitrate is prepared into a 40% solution, and sodium nitrite is prepared into a 5% solution. First, add a small amount of nitric acid solution and acetaldehyde solution to the reaction pot, then add sodium nitrite solution, slightly heat until brown-red gas occurs, naturally raise the temperature to 30 ℃, start dropping a small amount of nitric acid solution and acetaldehyde solution at the same time, add it for about 4 hours, control the reaction temperature at 40-45 ℃, add the escaped acetaldehyde gas to the reaction pot after being absorbed with water, and continue the reaction for 3 hours. The ingredients of acetaldehyde in the reaction are excessive (by molar ratio, nitric acid: acetic acid = 1:2). After the reaction is over, heat and recover acetaldehyde to 98°C. Then add activated carbon to decolorize, cool, filter and wash with water. The filtrate and lotion are combined, organic acids are distilled below 70 ℃(21.33kPa), and water is added repeatedly and then distilled until acidic cation exchange resin and weakly basic anion exchange resin in the distillate remove impurities. Exchange liquid and elution hydraulic concentration to obtain qualified concentration of glyoxal. In terms of acetaldehyde, the yield is about 32%.
Production method Generally commercial glyoxal is a 40% glyoxal solution, which is a colorless or slightly yellow liquid. It is easy to produce a white resin-like solid polymer when placed, and the polymer is turned into a liquid when heated.
In the presence of catalyst copper oxide, it is prepared by using 40% ethylene glycol aqueous vapor and air through an adiabatic quartz tube (aluminum oxide is used as a carrier in the tube, 40% silver catalyst) at 670 ℃. The one-way conversion rate is 84.5% and the selectivity is 50%.
It is also possible to oxidize acetaldehyde with nitric acid, and use copper nitrate as a catalyst for liquid phase oxidation with nitric acid. First, after 50% nitric acid and 50% acetaldehyde 1L and sodium nitrite are used for initiation under stirring, nitric acid and acetaldehyde are added dropwise at the same time. After adding the material, the acetaldehyde is reacted at 40~45 ℃ for 3h, and the acetaldehyde is recovered by heating under normal pressure, and the temperature is kept for 20min. Glyoxal is obtained by two decompression concentration processes of strongly acidic cation exchange resin and weakly basic anion exchange resin.

Last Update：2024-04-10 22:29:15