Benzo(c)pyran derivatives, process for their preparation and their use in perfumery.

Abstract

 Compounds having the formula:

wherein X represents a hydrogen atom, an alkyl group m has a value of 0 or 1, n has a value of 1 or 2 and n + m = 2 are prepared by cyclisation ot


They possess unique floral odours and are useful as ingredients of compounded perfumery compositions.
Especially valuable are thos compounds wherein X is hydrogen and n and m have a value of one.

Description

[0001] This invention is concerned with certain novel organic compounds and with perfumery compositions containing the compounds. It has been discovered that these compounds exhibit unique, attractive odours which render them useful in ingredients of perfumery compositions which compositions tina use in a wide variety of applications.

[0002] From our aspect our invention provides compounds of the formula:-

wherein X represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms and m has a value 0 or 1, n has a value 1 or 2 and n + m = 2 the dashed lines indicating alternative positions for a unit of unsaturation. Such compounds may be individual stereoisomers or mixtures of the possible stereoisomers of compounds having the above formula.

[0003] These compounds have been discovered to have a fresh-floral type of odour, with a blend of prominent neroili , bitter orange notes. Furthermore, the odours of these compounds blend harmoniously with those of other known odiferous chemicals to produce useful compounded perfumery compositions.

[0004] The novel compounds of this invention are derivatives of 3, 3, 7, 8 - tetramethyl - 2 - oxabicyclo - [4,4,0] - decane which will hereinafter be referred to for convenience as bigarade-oxides. They may be employed as a major ingredient of these compositions depending upon the desired overallodour required. In general the bigarade-oxides will constitute from 2 to 15, preferably 3 to 7 parts by weight of the composition. The perfumery compositions of this inventionmay find use as such or after dilution, but more usuallythey are added in small proportions to other materials such as space sprays or to soap cosmetic or deodorant compositions or to substrates such as fibre fabric or paper products in order to provide them with agreeable olfactory properties. Such compositions are products of commerce and they may comprise a simple or complex mixture of individual perfumery compounds.

[0005] Thus, from a second aspect our invention provides a compounded perfumery composition comprising a plurality of odiferous chemicals together with at least one compound having the formula:-

wherein X and m and n are as hereinbefore defined.

[0006] The unique fruity floral odours of the novel bigarade-oxides of our invention find special use in compositions designed for use in various perfumed bath preparations such as bath salts etc.

[0007] These novel perfumery compositions may be compounded according to recognised techniques of the perfumery arts employing known odoriferous perfumery ingredients such as those described in the standard textbooks of the art, e.g. "Soap, Perfumery and Cosmetics" by W.A. Poucher, 8th Edition, published by Chapman and Hall (London) 1974; "Perfume and Flavour Chemicals" by S. Arctander published by the author (Montclair) 1969 "Perfume and Flavour Materials of Natural Origin" also by S. Arctander self-published Elizabeth New Jersey (1960) and "Perfume Technology" by M. Billot and F.V. Wells published by Ellis Horwood Ltd. 1975. The relevant disclosures of these aforesaid textbooks are hereby incorporated by reference herein. Specific odoriferous ingredients which may be blended with the bigarade-oxides in a compounded perfumery composition are the derivatives of 2, 6-dimethyl-2-alkoxy octan-7-ol (as claimed in our Dutch Patent Application No. 72. 15238), vetivert oil, vetiverol, vetiveryl acetate guaic wood oil, esters of anthranilic acid such as the methyl, N methyl methyl, ethyl, phenyl-ethyl, cinnamyl, linalyl, methyl and geranyl esters, benzyl acetate, lemon oil, dimethyl benzyl carbinol, dimethyl benzyl car- binyl acetate, rose absolute, jasmin absolute, ionones, iso-nonyl acetate, methyl phenyl acetate, styrallyl acetate, B. phenyl ethanol, citronellol, citronellal, hydroxy citronnelal,geranium oil, geraniol, linalol, nerol, lavandin oil, linalyl acetate, patchouli oil, petitgrain oil, bergamot oil, heliotropin, ethylene brassylate, undecyl aldehyde, cinnamaldehyde, benzyl salicylate, cinnamyl alcohol, clove bud oil, bay oil, nutmeg oil, pimento berry oil, terpineol, ylang oil, benzyl benzoate, sandal-wood oil, clary sage oil, amyl salicylate, labdanum resin, methyl ionones, dihydro-myr- cenol, orange oil, vanillin, ethylvanillin, olibanum resin, musk ambrette, rhodinol, mandarin oil, methylnonyl acetaldehyde, neroli oil, cedrol, oak- moss, isovalanone, eugenol, iso-eugenol, cedarwood oil, p-tert-butyl cyclohexyl acetate.

[0008] Typically the novel bigarde-oxides are blended with at least two, usually at least five and preferably at least ten of the foregoing ingredients.

[0009] Preferred compounds for present use are those wherein X represents a methyl group or a hydrogen atom. Most preferably the isomers wherein n and m have a value of 1 are used.

[0010] Particularly preferred odoriferous ingredients for blending with the bigarade-oxides are linalol, linalylacetate, bergamot oil, grapefruit oil, lemon oil, orange oil, petitgrain oil, hexycinnamic aldehyde, benzylsalicylate, methyl ionones, 2-a_lkoxy-2, 6 dimethyl-octan-7-ols,

geraniol and nerol and esters thereof, neroli oil, farnesol, nerolidol. eugenol isceugenol, patchoulioil, vetiveryl acetate, cedryl acetate.

tiary butyl cyclohexyl acecate and terpineol.

[0011] may conveniently be maae



known as allo ocimene as its etarting

Allo acimene is readily available as a product of the thermal isomerisas of ocimene, a triene found as a constituent of several essential oils more usually from the thermal isomerisation of a pinene.

[0012] As a first step in this synthesis allo-ocimene is reacted with

urated dienophile having the formula: CH₂ = CXY the reaction being



addition. The reaction proceeds according to the follow- equation

[0013] The desired intermediate for the production of the novel compounds of the invention is the compound of formula:-



addition to a mixture of trans-trans and trans-cis allo-ocimene. When using a mixture of these two stereoisomers we prefer to carry out the reaction under elevated temperatures and pressures. When the low temperature catalysed reaction is employed the trans-cis isomer reacts extremely slowly. The Diels-Alder addition is probably stereospecific and the product which is preferably separated by fractional distillation comprises a mixture of the four stereoisomeric adducts having the above formula. These adducts are then converted to the corresponding alcohols. In the preferred case the aldehydes are reduced using the conventional technique of synthetic organic chemistry. Where other dienophiles are employed in the addition step such as an unsaturated carboxylic acid, carboxylic acid ester and car-. boxylic acid chloride the adducts are likewise converted to the corresponding alcohols using conventional techniques.

[0014] The conversion of the aldehyde to the corresponding alcohol may conveniently be achieved using catalytic hydrogenation i.e. heating the aldehyde adduct(s) at an elevated temperature of from 150°C to 170°C under superatmospheric pressure say 180 to 200 psi in an atmosphere of hydrogen gas and in the presence of a suitable catalyst. Preferably the catalyst employed is copper chromite but other conventional catalysts such as nickel, copper and palladium may be employed. Alternatively the reduction can be achieved using chemical methods in particular reduction with metal hydrides such as lithium aluminium hydride or sodium borohydride which reagents are normally added to the aldehyde as a solution in ether or water respectively, the reaction proceeding smoothly at ambient temperature. In conducting this reduction care should be taken to ensure that the ethylenic units of unsaturation present in the molecule are not attacked. The alcohols may be separated from the mixture of products formed using conventional techniques e.g. fractional distillation or used directly in the next stage in the synthesis.

[0015] the alcohol thus obtained may be cyclised to the bigarade-oxide by heating prefelably under reflux in the presence of a protonic acid catalys conveniently an aqueous solution of a mineral acid or phosphoric acid or

organic solution of a sulphonic acid. The reaction will usually go to

pletion under reflux within a period of a few hours e.g. 6 to 20 hours. Preferably an aqueous acid solution is employed as the catalyst. In order to speed the reaction a'relatively concentrated solution e.g. to 35% by weight is preferably employed in such a quantity that the volume of the aqueous phase is at least

EXAMPLE 5: Preparation of 3, 3, 7, 8 - tetramethyl-2-oxabicyclo-[4,4,0] dec-6-en.

[0016] 1500 mls of a 10% aqueous solution of phosphoric acid were added to 500 gm of the alcohol mixture obtained in (3) above and the solution refluxed gently with stirring for a period of 8 hours. The oil layer was separated and washed with dilute aqueous caustic alkali, dried over magnesium sulphate and distilled to yield the desired product.

EXAMPLE 6: Preparation of 3, 3, 7, 8-tetramethyl-2-oxabicyclo-[4,4,0] dec-6-enes and 3,3,7, 8-tetramethyl-2- oxabicycio- [4,4,0] dec-7-enes.

[0017] 3000 mls of a 30% aqueous solution of phosphoric acid were added to 1160 g of the alcohol mixture obtained in 3 above and the solution refluxed gently with stirring for a period of 12 hours. The oil layer was separated and washed with dilute aqueous caustic alkali and then water. The crude product was distilled to give a 74% yield of the six possible oxide isomers.

EXAMPLE 7: Preparation of 3,3,7, 8-tetramethyl-2-oxabicyclo-[4,4,0] dec-6-enes and 3,3,7, 8-tetramethyl-2- oxabicyclo- [4,4,0] dec-7-enes.

[0018] 20g of para-toluene sulphonic acid in 384g of ethylbenzene were added to 384g of the alcohol mixture obtained in 3 above and the solution was stirred at 70-80⁰C for 7.5 h. The reaction mixture was washed with dilute aqueous caustic alkali and then water. The crude product was distilled to give a 77% yield of the six possible oxide isomers.

EXAMPLE 8:

[0019] A compounded perfumery composition was made up as follow (all parts by weight):

Claims

1. A compound having the formula

wherein X represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, m has a value of 0 or 1, n has a value of 1 or 2, n+m = 2 and the dashed line indicates alternative positions for a unit of unsaturation.

2. A compound according to Claim 1 wherein X represents a methyl group.

3. A compound according to Claim 1 wherein X represents a hydrogen atom.

4. A compound according to any of the preceding Claims wherein n and m each have a value of 1.

5. A compounded perfumery composition which comprises a plurality of odiferous ingredients characterised in that it further comprises at least one compound having the formula I

wherein X represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, m has a value of 0 or 1 , n has a value of 1 or 2, n + m = 2 and the dashed line indicates alternative positions for a unit of unsaturation.

6. A composition according to claim 5 characterised in that X represents a hydrogen atom.

7. A composition according to either of Claims 5 or 6 characterised in that n and m each have a value of 1.

8. A composition according to any of Claims 5, 6 and 7 characterised in that the composition further comprises one or more odoriferous chemicals selected from the group comprising linalol, linalylacetate, bergamot oil, grapefruit oil, lemon oil, orange oil, petit grain oil, hexylcinnamic aldehyde, benzylsalicylate, methyl ionones, 2-alkoxy-2, 6 dimethyl-octan-7-ols, methylanthranilate, geraniol and nerol and esters thereof, neroli oil,farnesol nerolidol, eugenol, isoeugenol, patchouli oil, vetiveryl acetate, cedryl acetate, p tertiary butyl cyclohexyl acetate and terpineol.

9. A composition according to Claim 8 characterised in that the compounds of formula I comprise from 2 to 15 parts by weight thereof.

10. A composition according to Claim 9 characterised in that the compounds of formula 1 comprise from 3 to 7 parts by weight thereof.

11. A process for the preparation of a compound having the formula

wherein X represents a hydrogen atom or an alkyl group having from 1 to 4 carbon items, m has a value of 0 or 1, n has a value of 1 or 2, n + m = 2 and the dashed line indicates alternative positions for a unit of unsaturation characterised in that an alcohol having the formula

is cyclised by heating in the presence of an acid.

12. A process according to Claim 11 characterised in that the acid is phosphoric acid.

13. A process according to Claim 12 characterised in that an acid solution composing 15 to 35% by weight of acid is employed in a volume at least equal to that of the organic phase.

14. A process according to Claim 11 characterised in that the acid is present in the form of a solution of a sulphonic acid in an organic solvent.

15. A process according to Claim 14 wherein the acid is para toluene sulphonic acid.

16. A process according to Claim 11 substantially as hereinbefore described with reference to the foregoing examples.

17. A compounded perfumery composition according to Claim 5 substantially as foreinbefore described with reference to the foregoing examples.