1-Propanol

1-Propanol (also propan-1-ol, propanol, n-propyl alcohol) is a primary alcohol with the formula CH₃CH₂CH₂OH 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.

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.

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

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 PCl₃ with catalytic ZnCl₂ gives n-propyl chloride. Reaction with acetic acid in the presence of an H₂SO₄ 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 Na₂Cr₂O₇ and H₂SO₄ 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.

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.

A traditional laboratory preparation of 1-propanol involves treating n-propyl iodide with moist Ag₂O.