Acetylsalicylic acid structure, what is acetylsalicylic acid structure?

The structural formula is as follows:

Synthesis method. 1.Salicylic acid acetylation:

Add acetic anhydride (the amount of material is times the total amount of salicylic acid) in the reaction tank, then add two-thirds of the amount of salicylic acid, stir and raise the temperature, and react at 81-82 for 40-60min. Cool down to 81-82 and keep warm for 2h. After checking the free salicylic acid qualified, it was cooled to 13, crystallized and filtered, washed and dried with water, and dried at 65-70 gas to obtain acetylsalicylic acid.

2.Preparation method: In a dry reaction bottle, add 25g of dried salicylic acid (, 38g of acetic anhydride (, 1ml of concentrated sulfuric acid, and react in a 60 water bath for 30min.

After cooling, pour into 400ml of water, stir thoroughly, filter and wash. Recrystallization with 1:1 dilute acetic acid was used to obtain 32g of acetylsalicylic acid with a yield of 98%.

Note: It can also be purified by the following method: the crude product is dissolved in a small amount of hot ethanol, and then the hot ethanol solution is slowly added to the volume of hot water to form a transparent solution, and the acetylsalicylic acid needle-like crystals are slowly cooled and precipitated.

3.Method: Add 25g of dry salicylic acid (, 18ml of dried pyridine) to the reaction flask, and shake to dissolve.

Slowly add 21g of acetyl chloride dropwise, the reaction is exothermic, and the reaction temperature is controlled not to exceed 60. After addition, the reaction continued for 10min. Cool, pour 60ml of cold water and precipitate the solids.

Pumping, filtration, washing, and then recrystallization with 1:1 dilute acetic acid to obtain 22g of acetylsalicylic acid in yield. mp136 138 (128 135 partially decomposed).

The preparation of acetylsalicylic acid is synthesized by using salicylic acid and acetic anhydride as raw materials and concentrated sulfuric acid as catalysts.

Acetylsalicylic acid is slightly soluble in water, soluble in ethanol, soluble in ether and chloroform, and the aqueous solution is acidic.

Properties: white needle-like or plate-like crystalline or crystalline powder. Odorless, slightly sour.

The molecular chemical formula is: C9H8O4.

The molecular formula is: CH3COOC6H4COOH.

Molecular Relative Mass:.

CAS Number: 50-78-2.

Melting Point: 136-140.

Functions and uses of salicylic acid:

1. Standards for alkalinity and iodine titration. Fluorescent indicator, complexation indicator.

2. This product is used as an anti-scorch agent and the production of ultraviolet absorber and foaming agent in the rubber industry.

3. It is used as a matching indicator and masking agent. Titanium, zirconium, tungsten plasma chromogenic agent and preservative.

4. Salicylic acid is used as an additive in some weakly acidic electrolytes, and can also be used as a complexing agent for electroplating or electroless plating.

The relative molecular mass of acetylsalicylic acid is 180.

The structure of acetylsalicylic acid (commonly known as aspirin) is simply as follows: the relative molecular weight of aspirin is 180, which is a commonly used drug. Acetylsalicylic acid is a monobasic weak acid that is ionized in an aqueous solution.

At a certain temperature, the degree of ionization of acetylsalicylic acid is. then the pH of the solution is 2. To prepare 500 ml of this solution requires 180 g of acetylsalicylic acid.

Relative molecular weight

Relative molecular mass is the sum of the relative atomic masses (a) of each atom in the chemical formula, denoted by the symbol m, and the unit is 1. For polymers, their relative molecular weights can reach tens of thousands or even hundreds of thousands; The chemical formula of the oxide with the smallest relative molecular mass is Ho.

Copper sulphate: 160; sodium hydroxide: 40; Sulfuric acid: 98; Silver chloride:; Hydrochloric acid:; carbon dioxide: 44; Calcium hydroxide: 74; Phosphoric acid: 98; Ammonia: 17; Sodium chloride:.

Since the relative atomic mass of an element is a relative mass in the unit of "1", the molecular mass calculated from this must also be a relative mass in the unit of "1". For some biological macromolecules with complex structures, their approximate molecular mass is often measured by electrophoresis, centrifugation or chromatography, so it is a relative concept.

The salicylic acid structure formula is Ho-C6H4-COOH. Among them, phenolic hydroxy-OH and carboxy-COOH are in the ortho position, so they are called "o-hydroxybenzoic acid".

Stable at room temperature. Rapid pyrolysis into phenol and carbon dioxide. It has the general properties of some acid rushing rocks.

Phenol sodium salt solution is made with phenol and liquid caustic soda, vacuum dried, and then the dry carbon dioxide is slowly introduced at 100 times, and when the pressure is reached, the carbon dioxide is stopped, and the temperature is raised to 140 180. After the reaction is completed, clean water is added to dissolve the sodium salicylate salt, and then decolorization and filtration, and then sulfuric acid acidification is added, that is, salicylic acid is precipitated, and the finished product is obtained after filtration, washing and drying.