HEPTALDEHYDE & UNDECYLENIC ACID (C7 & C11) & ITS DERIVATIVES

Castor oil is non- edible oil obtained from castor seeds. Castor plant, Ricinus communis belonging to family, Europhobiaceae. India and China account for 50% of global castor oil production. The area under cultivation of Castor in India is about 5,00,000 acres and Andhra Pradesh accounts for 73% of this area. Castor oil is extracted for the seeds of castor either by local conventional methods or industrially in large quantities. Thus castor oil is available in plenty in our country. Many castor oil derivatives with lot of potential industrial use are not being manufactured in our country and they are being imported. These derivatives are used for surface coating materials, textile auxiliaries, perfumery chemicals, polymeric compounds and surfactants. Thus there is plenty of scope for developing indigenous methods for the production of such derivatives in large scale due to the availability of castor seeds in the country. This will not help easy availability of these derivatives in the local market it can also reduce the import burden on the exchequer.

The derivatives can also tap export potential to earn foreign exchange for the country. There are two important derivatives of castor oil, namely, Heptaldehyde and Undecylenic acid, which are produced by standard techniques. Heptaldehyde, which is by product of pyrolysis of castor oil, is used in perfumery industry since it has a natural fruity flavour. Heptaldehyde is a colourless liquid, oily, fruity odour, penetrating, hygroscopic, soluble in water, ether and combustible. This is oxidized to yield a hepatonic acid and by reducing it produces heptyl alcohol, which combines to form heptyl heptanes, a perfume which combines well with Coumarins. Hapatonic acid esters have variety of fruity flavours. Aldol condensation of heptaldehyde with bezakdehide yields amyl cinnamic aldehyde which is an important perfume.

Undecylenic acid as well as its zinc salt, are used as bactericidal, fungicidal and also used for diseases like athlete foot. Derivatives of this acid have extensive perfumery outlets. This alcohol has an intense penetrating odour and the saturated 11 carbon aldehyde is used in the modification of floral odours. Treatment of this acid with strong sulphuric acid gives gamma-Undecalcetone which is also called peach aldehyde.

A volume outlet for Undecylenic acid lies in the preparation of nylon 11, 11. Hydrobromination of the acid in presence of peroxide catalysts yields the terminal bromide which on heating melts and then condenses in head to tail fashion to yield a 11,11- polyamide called Rilsan having melting point of about 188 0C. It is a colourless to pale yellow liquid with a waxy and creamy constitution having molecular weight of 184.28 grams.

Undecylenic acid is the parent substance for the synthesis of several higher alcohals and aldehydes especially those containg nine and eleven carbon items. Noncyclic aldehyde can be obtained from Undecylenic acid or from heptaldehyde. Reduction of Undecylenic acid with sodium and alcohal converts its into Undecylenic alcohol which is chracterised by a flowery odour with a persisting fatty note. Reduction by free hydrogen in the presence of colloidal palladum as catalyst saturates the double bond producing Undecylenic acid which can be converted into Undecylic alcohal a valuable modifier and a tip note compound. This alcohol can be oxdised to give the corresponding aldehyde an equally important product for the perfumery industry.

Undecylenic acid is a synthetic unsaturated fatty acid. It is prepared from the natural product, ricinoleic acid, present in castor oil. Undecylenic acid is produced by cracking castor oil at high temperature and pressure.[not verified in body] It is the common name of 10 – undecenoic acid, abbreviated (CH2 = CH (CH2) 8COOH), and has two functional groups, a terminal alkene at one end, and a carboxylic acid at the other. It has use in synthetic chemistry and is used in the manufacture of pharmaceuticals, personal hygiene products, cosmetics, and perfumes. It also used as a topical antifungal agent.

PROPERTIES

The acid and its esters do not have any odour particularly, but the acid can be converted into lactose, which is often called in commerce as aldehyde C – 14. This lactose has a powerful and persistant odour of peaches esters of Undecylenic acid such as ethyl esters are useful to a limited extent as a flavouring agent. The more important esters of Undecylenic acid to the alyl esters. Which has a powerful odour of quinches used as a modifier –

Name – Undecylenic acid or Undecenoic acid

Formulae: CH2CH (CH2) 8COOH

It is a light coloured liquid.

It has a fruity – rosy odour,

It is almost unsoluble in water.

It is miscible with alcohal chloroform, ether, benezene and with fixed & volatile oils.

Its congealing point is 21oC.

Its specific gravity is 0.91 to 0.913 (at 25/25oC)

Its refracture index (25oC) is 1.4475 – 1.4485

Its flash point is 295oF or 146oC

It is combustable.

It has low toxity

GRADES Technical grade
Commercial grade