Title of Invention

A PROCESS FOR THE PREPARATION OF AROMATIC OILS FROM DAMMAR RESIN"

Abstract

A process for the preparation of aromatic oils from Dammar resin which comprises heating dammar resin under reduced pressure in the range of 10 to 200 mm Hg at a temperature in the range of 100 to 500°C, passing the vapours over 3 preheated catalyst on solid support and collecting the vapours under cryogenic conditions, purifying the collected vapours by conventional methods such as herein described to yield smoky-woody aromatic oil.

Full Text

"This invention relates to a process for me preparation of aromatic oils from Dammar resins, which are used in perfumery and flavour industry. These oils are rich in sesquiteipenes (particularly of cadalene type) with unique smoky-woody aroma. Therefore,these oils as such or in rectified' form or compounds thereof, may be used as such or in combination with other compounds for the said purpose. The invention describes a process for the pyrolytic depolymerisation of a resin polymer commercially known as dammar resin, obtained from SHOREA species growing abundantly in Central India, with an aim to obtain novel aromatic oils rich in sesquiterpene hydrocarbons of the cadalene type for use in perfumery and flavour industries,by volatilizing the powdered resin free from triterpenoids or as such at higher conditions of tempreature and reduced pressure,collecting the vapors under cryogenic conditions after passage over a solid support, maintained at high temperature to prevent the condensation of the high boiling vapors,dud the highly aromatic oil so obtained may be further rectified by fractional distillation and; or by treatment with organic acids or bases to yield light amber colored oils with novel and ^unique smoky -woody aroma. Dammar resins commonly known as Dhup or Ral are the naturally occurring resins originating from the trees of the family Dipterocarpaceae.A large amount of resins can be obtained by tapping of Shorea robusta trees in North and Central India, other Shorea spp.in East India and Vateria Indica in South India. It is estimated that about 5 lac tonnes of resin could be produced annually in India. Even larger amounts can be extracted from Indo-China region. Commercial dammar resin is a soft light yellow to brown solid. It has been in use since long as Phup in Hawan and pyre and in low grade soap and varnishes. Small amount of resin and sal wood is being destructively distilled to produce a dark coloured ofif also known as chua oil.In a typical process, the resin and sal wood is smoked slowly in a metallic vessel and the oily material trickles down through the perforated bottom of the vessel. There Is no prior art available on the subject except the references which discusses thej partial "chemical composition of the resin [JCS (1955) 3132J.S.Mills et al ;Phytochem (1977) 21|525699 W.M.Bandamayka et al;Ind.Drugs X1989)2262,146& 574,K.K.Purushothaman et al •Phytochem.U 981) 2212,957,.PBhartiya et al;Perf£ss.Oil.Rec.(1961)2522,233,S.CBhattacharya] Dammar or ral resins are the complex mixture of neutral and acidic triterpenes (30-40%),a macromolecule or a polymer of cadinene (60-65%) with a MW of 1000 to 10,000 which has been designated as B- resene, and several other mono-and sesqtiiterpenoids. The main object of the invention is to provide a process for the preperation of aromatic oil from Dammar resin obtained from Shorea species. Another objective of this invention is to convert dammar resins to more valuable perfumery and flavour chemicals.The invention describes a process for the pyrolytic depolymerisation of a resin polymer commercially known as dammar resin, obtained from SHOREA species growing abundantly in Central India, with an aim to obtain novel aromatic oils rich in sesquiterpene hydrocarbons of the cadalene type' for use in perfumery and flavour industries. The higher terpenoids and. polymers can be broken down. and depolymerised to smaller units with MW of upto 350, having: characteristic odour, and chemical properties. These compounds can further be utilized as raw'materials for the production of a variety of chemicals. Other objectives of this invention will be apparent to those skilled in the art. Accordingly, the present invention provides a process for I the preparation of aromatic oils from Dammar resin which comprises heating dammar resin under reduced pressure in the' range of 10 to 200 mm Hg at a temperature in the range of 100 o to 500 C, passing the vapours over a preheated catalyst on solid support and collecting the vapours under cryogenic conditions, purifying the collected vapours by conventlional methods such as herein described to yield smoky-woody aromatic oil. In an embodiment of the invention heating of dammar resin o ranges from 100-500 C. In another embodiment of the invention the solid support used may be such as salts of various metals and non metals like carbon, silicon, aluminium, titanium, copper, iron and nickel, porcellin chips. In still another embodiment the pH of the solid support catalyst may be in th'e range, of 2.5 to 10.5. In a feature of the invention pyrrolysis of the resin may be effected at reduced pressure in the range of 500 to 1 mm. In another feature of the invention purification may be effected by fractional distillation, steam distillation] and treatment with organic acids.and bases. The preswent invention provides a novel perfumery raw mate-rial and a process for its preparation which comprises pyroly-sis of resins under controlled conditions. The conversion of resins to hydronapthalene and cadalene derivatives of formula 1, 2, 3, 4, 5, 6 as shown in the drawings accompaning this complete specifications and other compounds with interesting perfumery and flavouring note's is effected by pyrolysis of odourless -resin. During pyrolysijls at !l temperature ranging from 200 -500 C and reduced pressure of 500 to 1 mm., these compounds are presumably derived from the unit structure of B-resene which is 1, 6-dimethyl-4 -isoprlopyl -1,2,3,4,6;7,8,8a-octahydronapthalene. The crude vapours are then allowed to rearrange into compounds of perfumery value over a range of catalysts. The catalyst may be neutral, acidic and basic (pH 2.5 to 10.5) on active supports, including salts of various metals and non metals like carbon, silicon, aluminium, titanium, copper, iron and nickel etc. The products so obtained are then further rectified by steam distillation and/or fractionation to yield finished oils and fractions having variety of odours ranging from smoky to woody vetiver like. Following examples are given by way of illustration and should not be construed as to limit the invention. Example 1 The total dammar resin (500 g) as such was heated at 300°C at a programmed rate of 4°C/min for 10 hours under reduced pressure (200 mm Hg) . The vapours formed during the reaction were allowed to pass on a preheated support (200°C) comprising of silica gel - alumina ( SiO2-Al2O3,2:3; 50 g). The gaseous distillate was trapped by using cryogenic traps and distilled oil collected (350 g).The oil so obtained gives a smoky woody aroma and further purified by fractional distillation . Example 2 The dried Shorea resin (500 g) was heated under vacuum (200 mm/Hg). The vapours formed were passed over heated porcelain chips kept at a temperature of 100°C. The contact time was only few seconds (10 Sec. ) so as to minimize the formation of undesired products. The hot distillate was subjected to cryogenic traps. The dark coloured oil was further purified by hydrodistillation, when it afforded a yellow liquid having woody, ionone like odour. The oil could find applications in perfumery as a substitute for Himalayan cedar wood oil or Virginian cedarwood oil. Example 3 The dammar fraction rich in ß resene ( 500 g) was taken in a three necked flask fitted with a thermometer, a pyrolysis tube containing the catalyst (5-20%) consisting of Nickel coated on silica gel and a vacuum connection. The resin was heated to reflux under vacuum of 10-15 mm/Hg and the vapours formed were passed over heated catalyst kept at a temperature of 300°C. The hot vapours were collected, in a cryogenic trap. The dark coloured oil obtained on cooling was distilled under vacuum to yield an amber yellow oil having woody odour. Example 4 The resin of S. robusta (500 g) was heated under vacuum, in a three necked flask fitted with a thermometer, a pyrolysis tube leading to a condenser. The vapours of the resin were passed over heated surface of glass wool containing 5-20% nickel sulphate and copper sulphate mixture kept at a temperature of 300°C. The reaction product on cooling gave a dark yellow oil (300 g) which was further purified by distillation under vacuum. The yellow oil gives a smoky woody ionone like aroma . We Claim : 1 . A process for the preparation of aromatic oils from Dammar resin which comprises heating dammar resin under reduced pressure in the range of 10 to 2.00 mm Hg at a tempera- o ture in the range of 100 to 500 C, passing the vapours over a preheated catalyst on solid support and collecting the vapours under cryogenic conditions, purifying the collected vapours. by conventional methods such as herein described to yield smoky-woody aromatic oil. 2. A process as claimed in claim 1 wherein the temperature o for pyrolysis is preferably 300 C. 3. A process as claimed in claims 1-2 wherein the pressure during pyrolysis is preferably 200 mm Hg. 4. A process as claimed in claims 1-3 wherein the solid support used is such as salts of various metals and non metals like carbon, silicon, aluminium, titanium, copper, iron, nickel and porcellin chips. 5. A process as claimed in claims 1-4 wherein the either acidic neutral or basic catalyst. 6. A process for the preparation of aromatic oils from Dammar resin substantially as herein described with reference to the examples..

Documents:

653-del-1997-abstract.pdf

653-del-1997-claims.pdf

653-del-1997-correspondence-others.pdf

653-del-1997-correspondence-po.pdf

653-del-1997-description (complete).pdf

653-del-1997-drawings.pdf

653-del-1997-form-1.pdf

653-del-1997-form-19.pdf

653-del-1997-form-2.pdf