Succinic acid, also known as succinic acid, is a kind of dicarboxylic acid. It is colorless crystal and tastes sour. It is soluble in water, ethanol and ether, but insoluble in chloroform and dichloromethane.

Succinic acid is colorless crystal; The relative density is 1.572 (25/4 ℃), the melting point is 188 ℃, and it decomposes at 235 ℃; Distillation under reduced pressure can sublimate; Soluble in water, slightly soluble in ethanol, ether and acetone.

In industry, succinic acid is usually prepared by catalytic reduction of maleic acid, and succinic acid can also be prepared by hydrolysis of Succinonitrile. In the laboratory, succinic acid can be prepared by reacting the sodium salt of diethyl malonate with iodine, and then hydrolyzing and decarboxylation.

The important use of succinic acid is to prepare five membered heterocyclic compounds. For example, succinic acid loses water rapidly when heated to form succinic anhydride, which is a furan ring compound. Succinic anhydride is an important raw material for the manufacture of drugs, dyes and alkyd resins. Succinic anhydride is co heated with ammonia to form succinimide. The hydrogen on the imine group of succinimide can be substituted by bromine to form N-bromosuccinimide, which is an organic bromination reagent and mild oxidant.

Succinic acid has antispasmodic, expectorant and diuretic effects in medicine. Diethyl succinate is an important intermediate in organic synthesis. Dibutyl succinate and dioctyl succinate are plasticizers for plastics. Diallyl succinate can be copolymerized with 1,3-butadiene to produce artificial rubber.