neopentyl glycol

Chemical properties

white solid

The Uses of neopentyl glycol

2,2-Dimethyl-1,3-propanediol may be used in the synthesis of:

• 2,2-dimethyl-1,3-propanediol cyclic phosphorochloridate
• 2,2-dimethyl-1,3-propanediol cyclic phenylphosphonate
• [1′,3′-(2′,2′-dimethylpropylene)]-2-iodo-3-octyl-5-thienylboronate
• cyclic carbonate
• 2,2-dimethyl-1,3-propanediol bis(cyclic-2,2-dimethyltrimethylene phosphite)

The Uses of neopentyl glycol

NPG Glycol is used in the synthesis of tetraphenylporphyrins. Also used in the synthesis of Bryostatin 2, a protein kinase modulator.

The Uses of neopentyl glycol

In the manufacture of plasticizers, polyesters, as modifier of alkyd resins.

Definition

ChEBI: Neopentyl glycol is a propane-1,3-diol carrying two methyl groups at position 2.

Preparation

3-hydroxy-2,2-dimethylpropanal) could be reduced to neopentyl glyco. Hydroxypivaldehyde can be reduced either by a crossed Cannizzaro reaction with equimolar amounts of formaldehyde and a base, or by catalytic hydrogenation. If inorganic bases such as potassium carbonate or sodium hydroxide are used as catalysts, satisfactory yields (ca. 80 %) of neopentyl glycol can be obtained only with an excess of isobutyraldehyde. Tertiary amines are also used as catalysts for the aldol addition. Catalytic transfer hydrogenation of the aldol intermediate is also possible using formate salts as hydrogen source. After fractional distillation a very good yield of high-purity neopentyl glycol is obtained.

General Description

White crystalline solid. Melting point 130°C.

Air & Water Reactions

Soluble in water.

Reactivity Profile

2,2-Dimethyl-1,3-propanediol may generate toxic gases in combination of with alkali metals, nitrides, and strong reducing agents. Reacts with inorganic acids and carboxylic acids to form esters plus water. Converted to aldehydes or acids by oxidizing agents. May initiate the polymerization of isocyanates and epoxides.
In addition to the reactions typical of primary alcohols, such as ester, ether, and carbamate (urethane) formation, 1,3-diols give six-membered cyclic derivatives with carbonyl compounds, carbonates, phosphites, sulfifites, and borates.

Health Hazard

May be harmful by ingestion or skin absorption. Causes eye and skin irritation. Material is irritating to mucous membrane and upper respiratory tract. INHALATION: Call for medical aid. Remove to fresh air. If breathing has stopped, give artificial respiration. If breathing is difficult, give oxygen.

Fire Hazard

Special Hazards of Combustion Products: Emits toxic fumes under fire condition.

Flammability and Explosibility

Non flammable

Solubility in water

Neopentyl glycol is soluble in water, alcohols, and ketones, moderately soluble in hot aromatic solvents, such as benzene and toluene, and relatively insoluble in aliphatic and cycloaliphatic solvents.

storage

During storage, higher temperatures and stacking pressures can lead to caking of the lower stack layers. As a hygroscopic material, 2,2-Dimethyl-1,3-propanediol must be stored dry. The product is also sold as 90 % aqueous solution, which should be stored at 55 – 60 ℃ to avoid precipitation, and as a 100 % melt.

Purification Methods

Crystallise the diol from *benzene or acetone/water (1:1). [Beilstein 1 IV 2551.]