Glyoxylic Acid CAS 298-12-4

A major use of glyoxylic acid is in the preparation of allantoin. Under certain temperature and catalyst, allantoin is formed by one-step condensation of glyoxylic acid and urea. The downstream products of allantoin include alcloxa, aldioxa, diazonium alkyl urea, polygalactonic acid and salicylic acid, ascorbic acid, glycine and other compounds of allantoin .

Allantoin series products are widely used in medicine, daily use, agriculture and other industries, and the prospects are very promising. In medicine, it is a drug with various functions, which can be used directly or as an additive; in the field of light chemical industry, it can be used as an additive in cosmetics; in agriculture, it can be used as a regulator of plant growth.

At present, allantoin in China is mainly used in medicine and daily chemical industry, and the annual demand is about 200t. Due to the high price of allantoin, its use in agriculture has not been fully opened. With the large-scale production of glyoxylic acid in my country, the consumption of allantoin will increase significantly. In 2003, the production cost of allantoin was 30,000 yuan, the market price was 50,000 yuan, and the economic benefit was very high.

Guaiacol and glyoxylic acid are condensed into 3-methoxy-4-hydroxyphenylglycolic acid in the presence of alkali, and then oxidized to remove CO2 under a catalyst to generate crude product, which is purified to make vanillin, that is, Friedel method. Vanillin is a broad-spectrum spice with elegant and refreshing aroma. It is directly used in cosmetics, soap, cigarettes, cakes, candies and baked goods.

In addition, vanillin is an important organic synthesis intermediate, which can produce such as 4,5-trimethoxybenzaldehyde (TMB), veratrol (3,4-dimethoxybenzaldehyde), catechin (3 , 4-dihydroxybenzoic acid) and many other products, the domestic prospects are very promising.

P-Hydroxyphenylacetic acid has developed rapidly in recent years, and its synthesis mainly adopts the route of phenol-glyoxylic acid. This method has simple process, less pollution and low cost, and is the main industrial production method at present. Phenol and glyoxylic acid first generate p-hydroxymandelate under alkaline conditions, then hydrolyze to p-hydroxymandelic acid, and finally reduce to p-hydroxyphenylacetic acid under catalyst.

p-Hydroxyphenylacetic acid has a wide range of uses, and is currently mainly used in the synthesis of p-hydroxyphenylacetamide (intermediate of the antihypertensive drug atenolol), health care medicine soy isoflavones (daidzein, puerarin, etc.), p-methoxyphenylacetic acid Phenylacetic acid (an intermediate of the new antidepressant venlafaxine), dermatological drugs butylbenzene hydroxy acid, p-hydroxyphenethyl alcohol, etc., have very promising prospects.

Atenolol is currently the best-selling antihypertensive drug in the world, and the demand at home and abroad is growing rapidly. p-Hydroxyphenethyl alcohol is prepared by the reduction of p-hydroxyphenylacetic acid, and is the raw material of cardiovascular drugs such as Metoprolol and Betaxolol.

Glyoxylic acid can be used to synthesize phenylglycine, including dl-phenylglycine (DLPG), lev-phenylglycine (DPG), etc., usually referred to as DPG. In production, dl-dihydantoin is generally prepared first, and then DPG is prepared. DPG is currently mainly used to synthesize β-lactam antibiotics, polypeptide hormones and pesticides, and is mainly used to synthesize β-lactam antibiotics in China.

Mandelic acid, which has R- and S-structures, is prepared by the reaction of benzene and glyoxylic acid. The price of mandelic acid and its salts and esters is very high.

Mandelic acid can be used to synthesize vasodilator cyclomandelic acid ester, ophthalmic drug oxybenzazole, central nervous system stimulant pimoline and benzodifuranone dye, in addition, mandelic acid can also synthesize acetophenone acid, which is a medicinal stomach. Changning and the raw materials of the highly effective and safe herbicide fenflumone currently on the market.