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Jai Ganesh

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Propanol

Propanol

Gist

Propanol is a kind of alcohol that contains three numbered carbon chains and alcoholic groups presented in either the first position (n-propanol) or second position (isopropanol) of the chain. Both these alcohols were prepared from renewable biomass feedstocks [50, 51].

Summary

What is N-Propanol? N-propanol (also known as 1-propanol, n-propanol alcohol, propan-1-ol, propyl alcohol) is a primary alcohol in which the OH entity is bonded to a primary carbon atom.

Propyl alcohol, also known as n-propyl alcohol or 1-propanol, is one of two isomeric alcohols used in chemical processing as solvents and intermediates.

It is most commonly used as a solvent in cosmetics and pharmaceuticals, as well as in lacquer preparation. It produces a variety of esters and ethers, some of which are commercially valuable.

Most commonly propanol is used as a solvent or it is used to produce other solvents such as antifreeze, lacquer formulations, soaps, dye solutions, window cleaners and more. Compounds of propanol like isopropanol or isopropyl alcohol are most commonly used in the printing industry and in printing ink.

Isopropyl alcohol (2-propanol) is made by indirect hydration of propylene (CH2CHCH3). Isopropyl alcohol is commonly used as an industrial solvent and as a rubbing alcohol applied to the skin.

Isopropanol, or isopropyl alcohol, is a clear, colorless liquid that emits an odor that resembles acetone. It is a commercially available product that mainly is found as a 70% solution in rubbing alcohol and hand sanitizers.

Details

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.

Occurrence

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

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.

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.

H2C=CH2 + CO + H2 → CH3CH2CH=O
CH3CH2CH=O + H2 → CH3CH2CH2OH

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

Safety

1-Propanol is thought to be similar to ethanol in its effects on the human body, but 2–4 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 (compared to 7.06 g/kg for ethanol). 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 lack of long term data, the carcinogenicity of 1-propanol in human beings is unknown.

1-Propanol as fuel

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

Isopropyl Alcohol

Isopropyl alcohol (IUPAC name propan-2-ol and also called isopropanol or 2-propanol) is a colorless, flammable organic compound with a pungent alcoholic odor.

Isopropyl alcohol, an organic polar molecule, is miscible in water, ethanol, and chloroform, demonstrating its ability to dissolve a wide range of substances including ethyl cellulose, polyvinyl butyral, oils, alkaloids, and natural resins. Notably, it is not miscible with salt solutions and can be separated by adding sodium chloride in a process known as salting out. It forms an azeotrope with water, resulting in a boiling point of 80.37 °C and is characterized by its slightly bitter taste. Isopropyl alcohol becomes viscous at lower temperatures, freezing at −89.5 °C, and has significant ultraviolet-visible absorbance at 205 nm. Chemically, it can be oxidized to acetone or undergo various reactions to form compounds like isopropoxides or aluminium isopropoxide. As an isopropyl group linked to a hydroxyl group (chemical formula (CH3)2CHOH) it is the simplest example of a secondary alcohol, where the alcohol carbon atom is attached to two other carbon atoms. It is a structural isomer of propan-1-ol and ethyl methyl ether. They all have the formula C3H8O.

It was first synthesized in 1853 by Alexander William Williamson and later produced for cordite preparation. It is produced through hydration of propene or hydrogenation of acetone, with modern processes achieving anhydrous alcohol through azeotropic distillation. Beyond its production, isopropyl alcohol serves in medical settings as a rubbing alcohol and hand sanitizer, and in industrial and household applications as a solvent. It is a common ingredient in products such as antiseptics, disinfectants and detergents. More than a million tonnes are produced worldwide annually. Despite its utility, isopropyl alcohol poses safety risks due to its flammability and potential for peroxide formation. Its ingestion or absorption leads to toxic effects including central nervous system depression and coma, primarily treated through supportive measures.

Properties

Isopropyl alcohol is miscible in water, ethanol, and chloroform, as it is an organic polar molecule. It dissolves ethyl cellulose, polyvinyl butyral, many oils, alkaloids, and natural resins. Unlike ethanol or methanol, isopropyl alcohol is not miscible with salt solutions and can be separated from aqueous solutions by adding a salt such as sodium chloride. The process is colloquially called salting out, and causes concentrated isopropyl alcohol to separate into a distinct layer.

Isopropyl alcohol forms an azeotrope with water, which gives a boiling point of 80.37 °C (176.67 °F) and a composition of 87.7% by mass (91% by volume) isopropyl alcohol. It has a slightly bitter taste, and is not safe to drink.

Isopropyl alcohol becomes increasingly viscous with decreasing temperature and freezes at −89.5 °C (−129.1 °F). Mixtures with water have higher freezing points: 99% at −89.5 °C (−129.1 °F), 91% (the azeotrope) at −75.5 °C (−103.9 °F), and 70% at −61.7 °C (−79.1 °F).

Isopropyl alcohol has a maximal absorbance at 205 nm in an ultraviolet-visible spectrum.

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