1-Propanol


1-Propanol is a primary alcohol with the formula and sometimes represented as PrOH or n-PrOH. It is a colourless liquid and an isomer of 2-propanol. 1-Propanol is used as a solvent in the pharmaceutical industry, mainly for resins and cellulose esters, and, sometimes, as a disinfecting agent.

History

The compound was discovered by Gustave Chancel in 1853 by fractional distillation of fusel oil. He measured its boiling point at 96°C, correctly identified its empirical formula, studied some of its chemical properties and gave it two names: propionic alcohol and hydrate of trityl.
After several unsuccessful attempts, it was synthesized independently and by two different routes by Eduard Linnemann and Carl Schorlemmer in 1868.

Occurrence

s like 1-Propanol are grain fermentation byproducts, and therefore trace amounts of 1-Propanol are present in many alcoholic beverages.

Chemical properties

1-Propanol shows the normal reactions of a primary alcohol. Thus it can be converted to alkyl halides; for example red phosphorus and iodine produce n-propyl iodide in 80% yield, while phosphorus trichloride| with catalytic Zinc chloride| gives n-propyl chloride. Reaction with acetic acid in the presence of an sulfuric acid| catalyst under Fischer esterification conditions gives propyl acetate, while refluxing propanol overnight with formic acid alone can produce propyl formate in 65% yield.
Oxidation of 1-propanol with Sodium dichromate| and gives a 36% yield of propionaldehyde, and therefore for this type of reaction higher yielding methods using PCC or the Swern oxidation are recommended. Oxidation with chromic acid yields propionic acid.

Preparation

1-Propanol is manufactured by catalytic hydrogenation of propionaldehyde. Propionaldehyde is produced via the oxo process by hydroformylation of ethylene using carbon monoxide and hydrogen in the presence of a catalyst such as cobalt octacarbonyl or a rhodium complex.
Other proposed industrial processes include the two-step isomerization and hydrogenation of propylene oxide.
A traditional laboratory preparation of 1-propanol involves treating n-propyl iodide with moist silver oxide|.

Safety

1-Propanol is thought to be similar to ethanol in its effects on the human body, but 2 to 4 times more potent according to a study conducted on rabbits. Many toxicology studies find oral acute LD50 ranging from 1.9 g/kg to 6.5 g/kg. It is metabolized into propionic acid. Effects include alcoholic intoxication and high anion gap metabolic acidosis. As of 2011, one case of lethal poisoning was reported following oral ingestion of 500mL of 1-propanol. Due to a lack of long term data, the carcinogenicity of 1-propanol in humans is unknown.

1-Propanol as fuel

1-Propanol has a high octane number and is suitable for use as engine fuel. However, propanol is too expensive to use as a motor fuel. The research octane number of propanol is 118, and the anti-knock index is 108.