Preparation of p-diacetoxybenzene_Kain Industrial Additives

Background and overview^[1]

P-Diacetoxybenzene is the dimethyl ester derivative of p-diphenol and can be used as an intermediate for pharmaceutical and chemical synthesis. If para-diacetoxybenzene is inhaled, move the patient to fresh air; if skin contact occurs, take off contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical attention if you feel unwell; if contact with eyes, remove The eyelids should be separated, rinsed with running water or saline, and seek medical attention immediately; if ingested, rinse mouth immediately, do not induce vomiting, and seek medical attention immediately.

Structure

Preparation^[1]

The preparation of p-diacetoxybenzene is as follows: open the feeding port of the batching kettle, and manually mix the weighed p-hydroxybenzoic acid, hydroquinone, and 6-hydroxy-2-naphthoic acid at a ratio of about 10:2: 7 into the feeding kettle, then add sulfamic acid (catalyst) into the feeding kettle, pump acetic anhydride directly into the feeding kettle, stir and use jacketed steam to heat up to 60 degrees, then put the material into the acetylation kettle, stir, and use The heat transfer oil in the jacket of the electric thermal oil boiler is heated to about 140 degrees and refluxes for 4 hours. After the acetylation is completed, a small flow of nitrogen is passed through to begin to distill out the product acetic acid. During the distillation process, trace amounts of nitrogen are continuously introduced until the temperature is about 160 degrees. The basic distillation of acetic acid is completed, and the product hydrogenamine (hydrogenated benzoin) is obtained. The acetic acid produced during the acidification process is condensed and collected and sold as a by-product. In this reaction, based on p-hydroxybenzoic acid, hydroquinone and 6-hydroxy-2-naphthoic acid, acetic anhydride is slightly excessive, and p-hydroxybenzoic acid, hydroquinone and 6-hydroxy-2-naphthoic acid are basically completely reacted. The reaction yield is 100% and there are no side reactions. The reaction equation is as follows:

Main reference materials

[1] CN201710126046.1 A production method of liquid crystal polymer LCP