Диизобутилкарбонат

Substance identification

Diisobutyl carbonate is a diester of carbonic acid and isobutyl alcohol. English name Diisobutyl carbonate, CAS 539-92-4, formula C9H18O3, section “Esters”. Synonyms: Isobutyl carbonate, carbonic acid bis(2-methylpropyl) ester, NSC number 4009.

Basic Attributes

• CAS No.: 539-92-4
• Formula: C9H18O3
• Molecular weight: 174.24; exact mass 174.24
• EU number: 208-730-3
• UNII:UN7NR8B1XJ
• NSC Number: 4009
• DSSTox ID: DTXSID4060236
• HS Code: 2920909090
• PSA: 35.5; XLogP3: 2.4516

Physico-chemical characteristics

• Density: 0.9130 g/cm3 at 20 °C
• Boiling point: 190°C
• Flash point: 71.5 °C
• Refractive index: 1.416

Substance class and application

Diisobutyl carbonate belongs to dialkyl carbonates - esters of carbonic acid, where the carbonate group binds two isobutyl radicals through oxygen atoms. Like the related dimethyl, diethyl and diisopropyl carbonates, the substance is used as an environmentally friendly aprotic solvent and a mild alkoxycarbonylating reagent, transferring an alkoxycarbonyl group to nucleophiles without the formation of halide wastes characteristic of chloroformates. Such carbonates are used in the synthesis of carbamates and polyurethanes, as components of non-aqueous electrolytes and solvents for paint and varnish compositions. Dialkyl carbonates are classified as “green chemistry” reagents because the byproduct of their reactions with nucleophiles is a low molecular weight alcohol, rather than the hydrogen chloride or halide salt characteristic of classical carbonylating agents based on phosgene and chloroformates. The longer and more branched isobutyl chain compared to the isopropyl analogue gives the product a higher boiling point and greater hydrophobicity, which expands the operating temperature range of the technological processes where the reagent is used.

Storage and transportation

Data on transport codes, hazard categories and GHS markings are not provided in the source. As an ester of carbonic acid, sensitive to hydrolysis, the substance is stored in an airtight container, in a cool, dry room, away from strong acids and alkalis that catalyze the decomposition of the carbonate bond. The moderate flash point (71.5 °C) requires standard fire safety measures when overfilling large volumes: keep away from open flames and sparking sources, use explosion-proof equipment.

Additionally

The refractive index of 1.416 and density of 0.9130 g/cm3 are convenient for quick express control of a batch of product using a hydrometer and refractometer when receiving raw materials in production. After opening, it is recommended to close the container quickly to limit the absorption of atmospheric moisture and preserve the content of the main substance. The section of the classifier “Ethers” reflects that the substance belongs to ester reagents used as solvents and intermediate products, and not as finished commercial products for final use.