CAS number: 7400-08-0 Molecular formula: C9H8O3 Molecular weight: 164.16 EINECS: 231-3000-0 Content: 99% Appearance: white or light yellow powder. Relative density: 1.07 Melting point: 218-221 ° C Medical aspect It can be used for the synthesis of azalea, a new expectorant drug. It can be used as an intermediate in the production of cortisone for the treatment of coronary heart disease in the pharmaceutical industry, as well as for the manufacture of local anesthetics, bactericides and hemostatic agents. Can be used to synthesize the anti-adrenalin drug esmolol. 2. Agriculture In the pesticide industry, it is used to produce plant growth promoters, long-acting fungicides and fruit and vegetable preservatives. In addition, p-hydroxycinnamic acid can also be used as a chemical reagent for the determination of uranium and hunger, and is used as the main raw material for the production of photosensitive resins. 3. Cosmetics Parahydroxycinnamic acid can inhibit the activity of tyrosinase monophenolase and diphenolase, resulting in a 50% decrease in monophenolase activity and diphenolase activity. It is used in cosmetics to inhibit melanin production. 4. Chemical industry 1) P-hydroxycinnamic acid is a very important flavor and fragrance. The permitted fragrances are mainly used to configure spices such as spicy cherry, apricot and honey. Used in the daily chemical industry to formulate soap and cosmetic essence. 2) P-hydroxycinnamic acid is also a powerful conductive material, which has been widely studied in the liquid crystal display industry in recent years. The photo-sensitive para-hydroxy polyimide was synthesized by the graft reaction of hydroxy polyimide and para-hydroxycinnamic acid, and the structure of the photo-sensitive para-hydroxy polyimide was determined by infrared and nuclear magnetic resonance. The synthesized para-hydroxy polyimide was used as a liquid crystal alignment layer in a liquid crystal display device, and proved to have good thermal stability