Preparation of phenylene glycol acetal_Kain Industrial Additive

Background and overview^[1][2]

The carbonylation reaction of aldehydes or ketones is a very important organic reaction and is often used for carbonyl protection in multi-step synthesis. Carbonyl compounds are not only important pharmaceutical intermediates, but also important chemical products used in industries such as food additives, spices, surfactants and polymer materials. Traditionally, the methods for synthesizing acetals and ketal compounds mostly use catalytic methods such as inorganic acids such as HCl, HSO, BF, EtO and TFA. The reaction yield is low and the amount of catalyst is large. The use of inorganic acids also causes pollution and corrosion of equipment. defect.

Research in recent years has found that solid super acids, metal salts, ionic solutions and organic acids (such as p-toluenesulfonic acid) can be used in acetalization and ketalization reactions with high reaction yields. However, However, there are disadvantages in that using catalysts is expensive, toxic and complicated to prepare.

Phenylacetaldehyde dimethylcarboxaldehyde can be used as an intermediate for pharmaceutical and chemical synthesis. If phenylacetaldehyde is inhaled, please move the patient to fresh air; if the skin comes into contact, take off contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical treatment if you feel uncomfortable; if the eye contact , you should separate your eyelids, rinse with running water or saline, and seek medical attention immediately; if ingested, rinse your mouth immediately, do not induce vomiting, and seek medical attention immediately.

Structure^[1]

Phenylene glycol acetal can be used as an intermediate for pharmaceutical and chemical synthesis. For example, it can be used to prepare a mimosa essence. Mimosa is a perennial herb or subshrub of the Leguminosae family. The leaves react to heat and light and will close immediately when touched by external force, hence the name Mimosa. Mimosa essential oil contains a certain amount of mimosine, which is slightly toxic. Long-term exposure or consumption can cause the hair follicles in skin cells to decay, causing hair and eyebrows to turn yellow or even fall off. Therefore, the market needs a fragrance that can replace Mimosa essential oil.

The components and the mass fractions of each component are: 1-3 parts of p-cresol methyl ether, 0.1-1 part of indolin, 3-6 parts of cinnamic alcohol, 0.5-1.5 parts of cinnamic aldehyde, acetic acid 17-20 parts of benzyl ester, 1-3 parts of benzyl butyrate, 2-4 parts of benzyl alcohol, 17-18 parts of terpineol, 3-4 parts of phenethyl acetate, 7-8 parts of phenylacetaldehyde dimethyl acetal parts, 1-2 parts of isoeugenol, 2-3 parts of geraniol, 1-2 parts of styrax acetate, 8-9 parts of aldol, 4-5 parts of nerolidin, 3-4 parts of benzyl benzoate , 16-17 parts of linalool, 0.1-0.5 parts of p-cresol acetate, 2-3 parts of p-cresol phenylacetate, 3-4 parts of phenethyl alcohol, 1-2 parts of methyl hexyl cinnamic acid, cinnamic acid 2-3 parts of ester.

Preparation^[2]

The specific steps are as follows: Add phenylacetaldehyde (0.2mol, 24g), hydrogen-carrying catalyst AcrH 0.26g, and methanol 100mL to a four-necked flask equipped with a stirrer and a thermometer in sequence, stir and react at room temperature for 24h; react After completion, excess methanol was first recovered by distillation, and then distilled under reduced pressure to obtain 27.2 g of phenylacetaldehyde dimethyl acetal, a light yellow liquid with a light and elegant fragrance, with a yield of 82%.

HNMR(600MHz, CDCl) δ7.30(d,J＝7.6Hz,2H),7.24(s,2H),7.21(d,J＝7.2Hz,1H),4.54 (t,J＝5.6Hz ,1H),3.34(s,6H),2.91(s,2H);

NMR(151MHz, CDCl)δ137.03(s),129.40(s),128.29(s),126.34(s),105.34(s),53.31(s),39.67(s).