Sebacic acid

Sebacic acid (decandia acid) HOOC(CH2)8СООН — limiting dibasic carboxylic acid(lat. sebaceus — candle oil, lard). Has all the chemical properties, characteristic of carboxylic acids. Salts and esters sebacic acid called sabatinelli.

In industry, sebacic acid the acid is derived primarily from castor oil. When heated with water (200-225 °C; 1.8 to 2.5 MPa) produces glycerol and a mixture of carboxylic acids, contains 80-85% of ricinoleic acid; the decomposition of the latter with alkali at 250 °C with the subsequent saponification of the resulting sebacate sodium mineral acids leads to the release of sebacic acid (yield — 35-40 %, based on castor oil).

Promising method of obtaining sebacic acid — anodic condensation of monomethylamine to dimethylcarbonate with subsequent hydrolysis of the diester. The process is carried out in methanol on the electrodes of platinized titanium at current density of 600-1500 A/m2, a temperature of 45-55 °C, hydrolysis of the diester is carried out in excess water (220-240V °C; 3,9-4,9 MPa); a yield of sebacic acid in this case is 70-75 %.

When recovering sebacic acid formed 1,10-decandiol; under the action of Br2 on sebacate silver 1.8 dibromobutan; in the dehydration of the ammonium salt or the diamide — sebaconitrile. Heating sebacic acid with acetic anhydride leads to the formation of unstable polymeric anhydride, which cleaves CO2 and into ciclesonide.

Sebacic acid is able to polycondensation with bifunctional compounds: a glycol forms polyethers [-OROCO(CH2)8CO-]n; with diamines and amino alcohols are the corresponding polyamides and polyaminoamide [-XRNHCO(CH2)8CO-]n (X = O, NH).

The temperature of decarboxylation 350-370 °C.

Enthalpy of combustion (ДН0сгор) -5409,4 kJ/mol.