General Description
A colorless liquid with a pungent odor. Less dense than water and poorly soluble in water. Hence floats on water. Very corrosive. Contact may likely burn skin, eyes, and mucous membranes. May be toxic by ingestion, inhalation and skin absorption. Flash point near 200°F.
Reactivity Profile
HEPTANOIC ACID(111-14-8) reacts exothermically with bases. Can react, particularly if moist, with active metals to form gaseous hydrogen and a metal salt. Such reactions are slow if the acid remains dry. Corrodes or dissolves iron, steel, and aluminum parts and containers under ordinary conditions. Reacts with cyanide salts to generate gaseous hydrogen cyanide, particuarly if moist. May generate flammable and/or toxic gases with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Reacts with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Reacts exothermically with carbonates and bicarbonates to generate a harmless gas (carbon dioxide). Can be oxidized exothermically by strong oxidizing agents and reduced exothermically by strong reducing agents. A wide variety of products is possible. May initiate polymerization reactions; may catalyze chemical reactions.
Air & Water Reactions
Slightly soluble in water.
Health Hazard
Harmful if swallowed, inhaled, or absorbed through skin. Extremely destructive to mucous membranes, upper respiratory tract, skin, and eyes. Inhalation may be fatal as a result of spasm, inflammation and edema of the larynx and bronchi, chemical pneumonitis, and pulmonary edema. Symptoms of exposure may include burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea, and vomiting.
Fire Hazard
This chemical is probably combustible.
Chemical Properties
Heptanoic acid has a disagreeable rancid odor. The spectroscopically pure acid exhibits a faint tallow-like odor. Heptanoic acid
may be prepared by oxidation of heptaldehyde with potassium
permanganate in diluted sulfuric acid.
Occurrence
Reported as occurring naturally in calamus, hops, Acacia dealbata, and Japanese peppermint and violet leaves; its presence in rancid oils has been observed Also reported found in passion fruit, mandarin orange peel oil, guava, apple, banana, grapes, papaya, raspberry, strawberry, kiwi, baked potato, sauerkraut, tomato, breads, cheeses, butter, milk, fsh, fsh oil, meats, chicken fat, pork fat, hop oil, beer, cognac, brandy, rum, grape wines, sherry, whiskies, sake, peated malt, cocoa, coffee, tea, soy protein, peanuts, pecans, coconut, beans, mushroom, fenugreek, mango, fgs, licorice, corn oil, shrimps, scallops and other sources
Definition
ChEBI: A C7, straight-chain fatty acid that contributes to the odour of some rancid oils. Used in the preparation of esters for the fragrance industry, and as an additive in cigarettes.
Preparation
By oxidation of heptaldehyde with potassium permanganate in diluted sulfuric acid.
Production Methods
The methyl ester of ricinoleic acid, obtained from castor bean oil is the main commercial precursor to heptanoic acid. It is hydrolyzed to the methyl ester of [[undecenoic acid]] and heptanal, which is then air oxidized to the carboxylic acid. Approximately 20,000 tons were consumed in Europe and US in 1980.
Ricinoleic acid is the main precursor to heptanoic acid. Heptanoic acid is used in the preparation of esters, such as ethyl heptanoate, which are used in fragrances and as artificial flavors. Heptanoic acid is used to esterify steroids in the preparation of drugs such as as testosterone enanthate, trenbolone enanthate, drostanolone enanthate and methenolone enanthate (Primobolan). It is also one of many additives in cigarettes.
Taste threshold values
Taste characteristics at 5 ppm: waxy, cheesy, fruity, dirty and fatty.
