2-Cyclopropyl-4-isopropyl-2,5,5-trimethyl-1,3-dioxane as odorant

Abstract

A perfumery composition consisting essentially of from 1% to 50% by weight of a 4-isopropyl-5,5-dimethyl-1,3-dioxane of the formula ##STR1## wherein R.sub.1 and R.sub.2 are individually members selected from the group consisting of hydrogen, alkyl having from 1 to 3 carbon atoms and cyclopropyl, and the remainder customary constituents of perfumery compositions; as well as novel 4-isopropyl-5,5-dimethyl-1,3-dioxanes of the above formula wherein both R.sub.1 and R.sub.2 are not simultaneously hydrogen.

Description

BACKGROUND OF THE INVENTION

The present invention relates to perfumery compositions containing 4-isopropyl-5,5-dimethyl-1,3-dioxanes and the novel 2-substituted-4-isopropyl-5,5-dimethyl-1,3-dioxanes.

The use of alkylated 1,3-dioxanes as perfumes is already known from British patent specification No. 981,285, relating to compounds of the general formula ##STR2## in which R.sub.1 represents an alkyl radical having 4 to 9 carbon atoms, R.sub.2 represents hydrogen or an alkyl radical having 1 to 4 carbon atoms, and R.sub.3 represents hydrogen or a methyl radical. According to patent specification No. 981,285, it is essential to observe the following conditions in order to obtain usable perfumes: (1) the number of carbon atoms of the straight- or branched-chain alkyl radical R.sub.1 located in the 2 position must be at least 4 but no more than 9, (2) the substituent in the 4 position must only be a methyl radical, and (3) each ring carbon atom must carry at least one hydrogen atom. By virtue of these conditions of the said patent specification which greatly limit the breadth of the generic formula, it was not to be anticipated that compounds, hving other than the structure initially specified, would possess perfume qualities.

Copending, commonly-assigned U.S. patent application Ser. No. 806,616, filed June 15, 1977 now U.S. Pat. No. 4,124,541, relates to the use of alkyl-substituted 1,4-dioxanes for use in perfumery compositions of the formula ##STR3## Here again, each ring carbon must carry at least one hydrogen atom, and, of course, the compound is a 1,4-dioxane.

OBJECTS OF THE INVENTION

An object of the present invention is the development of a perfumery composition with characteristic fragrances ranging from fruity, herbal to woody.

A further object of the present invention is the development of a perfumery composition consisting essentially of from 1% to 50% by weight of a 4-isopropyl-5,5-dimethyl-1,3-dioxane of the formula ##STR4## wherein R.sub.1 and R.sub.2 are individually members selected from the group consisting of hydrogen, alkyl having from 1 to 3 carbon atoms and cyclopropyl, and the remainder customary constituents of perfumery compositions.

A yet further object of the present invention is the obtaining of a 4-isopropyl-5,5-dimethyl-1,3-dioxane of the formula ##STR5## wherein R.sub.1 and R.sub.2 are individually members selected from the group consisting of hydrogen, alkyl having from 1 to 3 carbon atoms and cyclopropyl, with the proviso that R.sub.1 and R.sub.2 are not both hydrogen.

These and other objects of the present invention will become more apparent as the description thereof proceeds.

DESCRIPTION OF THE INVENTION

We have now found that 4-isopropyl-5,5-dimethyl-1,3-dioxanes of the following general formula I can be used in an advantageous manner as perfumes having a wide variety of fragrances: ##STR6## in which R.sub.1 and/or R.sub.2 represent hydrogen or an alkyl or cycloalkyl radical having 1 to 3 carbon atoms.

More particularly, the invention relates to a perfumery composition consisting essentially of from 1% to 50% by weight of a 4-isopropyl-5,5-dimethyl-1,3-dioxane of the formula ##STR7## wherein R.sub.1 and R.sub.2 are individually members selected from the group consisting of hydrogen, alkyl having from 1 to 3 carbon atoms and cyclopropyl, and the remainder customary constituents of perfumery compositions.

Some of the 2-substituted-4-isopropyl-5,5-dimethyl-1,3-dioxanes are novel products. These are particularly 4-isopropyl-5,5-dimethyl-1,3-dioxanes of the formula ##STR8## wherein R.sub.1 and R.sub.2 are individually members selected from the group consisting of hydrogen, alkyl having from 1 to 3 carbon atoms and cyclopropyl, with the proviso that R.sub.1 and R.sub.2 are not both hydrogen.

The use of the above 4-isopropyl-5,5-dimethyl-1,3-dioxanes in perfumery was completely unexpected in view of the teachings of British Pat. No. 981,285 as discussed above. The compounds of the present invention have one or two ring carbons without hydrogen atoms. The substituent in the 4 position is isopropyl and the substituents R.sub.1 and/or R.sub.2 must have 3 or less carbon atoms. Any supposition that the compounds of formula I would have any use in perfumery was further invalidated by virtue of the fact that 2-alkyl substituted compounds of formula I, in which at least one of the radicals R.sub.1, R.sub.2 had more than 3 carbon atoms, such as 2-ethyl-2-butyl-4-isopropyl-5,5-dimethyl-1,3-dioxane or 2,2-dibutyl-4-isopropyl-5,5-dimethyl-1,3-dioxane, were not suitable for perfumes, although they fulfilled the requirements of the British patent specification for a substituent having 4 to 9 carbon atoms in the 2 position.

The 4-isopropyl-5,5-dimethyl-1,3-dioxanes of the structure specified, and which, in accordance with the invention, are to be used as perfumes, are produced by conventional methods of organic chemistry by acetalization or ketalization of 2,2,4-trimethylpentanediol-(1,3) with aliphatic aldehydes or ketones in the presence of an acidic catalyst, respectively, according to the reaction diagram: ##STR9## where R.sub.1 and R.sub.2 have the above-assigned values.

Thus, for example, Baltz et al have described the compound 4-isopropyl-5,5-dimethyl-1,3-dioxane in the "Journal fur praktische Chemie" 29: 250-258 (1965), without recognizing its perfume character or mentioning its possibilities of use.

More particularly, the invention also relates to a process for the production of a 4-isopropyl-5,5-dimethyl-1,3-dioxane of the formula ##STR10## wherein R.sub.1 and R.sub.2 are individually members selected from the group consisting of hydrogen, alkyl having from 1 to 3 carbon atoms and cyclopropyl, with the proviso that R.sub.1 and R.sub.2 are not both hydrogen, which consists essentially of the step of reacting 2,2,4-trimethylpentanediol-(1,3) with a compound of the formula ##STR11## wherein R.sub.1 and R.sub.2 have the above-assigned values under ketalization conditions in the presence of an acidic catalyst, and recovering very 4-isopropyl-5,5-dimethyl-1,3-dioxane.

4-isopropyl-5,5-dimethyl-1,3-dioxanes to be used in accordance with the invention are, for example, 4-isopropyl-5,5-dimethyl-1,3-dioxane, 4-isopropyl-2,5,5-trimethyl-1,3-dioxane, 2-ethyl-4-isopropyl-5,5-dimethyl-1,3-dioxane, 2,4-diisopropyl-5,5-dimethyl-1,3-dioxane, 4-isopropyl-2,2,5,5-tetramethyl-1,3-dioxane, 2-ethyl-4-isopropyl-2,5,5-trimethyl-1,3-dioxane, 2,2-diethyl-4-isopropyl-5,5-dimethyl-1,3-dioxane, 2-cyclopropyl-4-isopropyl-2,5,5-trimethyl-1,3-dioxane, 2,4-diisopropyl-2,5,5-trimethyl-1,3-dioxane, 2,2,4-triisopropyl-5,5-dimethyl-1,3-dioxane, and 2-cyclopropyl-4-isopropyl-5,5-dimethyl-1,3-dioxane. Moreover, the 2-substituted products constitute new compounds.

The 4-isopropyl-5,5-dimethyl-1,3-dioxanes to be used in accordance with the invention are valuable perfumes having characteristic fragrances ranging from fruity, herbal to woody. A particular advantage of the perfumes in accordance with the invention is that they are capable of being combined very satisfactorily to form novel fragrances in the perfumery compositions of the invention.

The 4-isopropyl-5,5-dimethyl-1,3-dioxanes to be used, in accordance with the invention, as perfumes, can be mixed with other perfumes in a wide range of quantity ratios to form novel perfumery compositions. In general, the proportion of the 4-isopropyl-5,5-dimethyl-1,3-dioxanes to be used in the perfumery compositions according to the invention will vary from 1% to 50% by weight relative to the total perfumery composition. The remainder of the composition is conventional perfumery constituents. Such compositions can act directly as a perfume or, alternatively, can be used to perfume cosmetics such as creams, lotions, toilet waters, aerosols, toilet soaps, etc. However, as is possible with the 4-isopropyl-5,5-dimethyl-1,3-dioxanes themselves, they can also be used to improve the odor of technical products such as washing and cleaning agents, disinfectants, agents for treating textiles, etc.

The following Examples are intended to further explain the subject of the invention, but without any implied limitation to these Examples.

EXAMPLES

The method for the production of representative 4-isopropyl-5,5-dimethyl-1,3-dioxanes will be given first by two procedures. The remaining products are made comparably.

Production of 4-isopropyl-5,5-dimethyl-1,3-dioxane (Example 1)

146 gm(1 mol) of 2,2,4-trimethylpentanediol-(1,3), 33 gm (1.1 mol) of paraformaldehyde, 60 ml of ethylenechloride and 0.1 ml of concentrated sulfuric acid were heated in a reactor connected to a water separator until no further water was recovered azeotropically, which took approximately 2 hours. 1.5 gm of sodium carbonate was then added to the mixture and the major quantity of the ethylenechloride was distilled off at normal pressure (sump temperature up to 155.degree. C.). The residue remaining was subsequently fractionally distilled under vacuum. 150 gm of 4-isopropyl-5,5-dimethyl-1,3-dioxane having a b.p..sub.20 =71.degree. C. were obtained, corresponding to a yield of 95% of theory.

Production of 4-isopropyl-2,2,5,5-tetramethyl-1,3-dioxane (Example 5)

292 gm (2 mol) of 2,2,4-trimethylpentanediol-(1,3), 108 gm (2.02 mol) of acetone, 296 gm (2 mol) of orthoformic acid triethylester and 0.4 gm of p-toluene sulfonic acid were agitated for 1 hour at room temperature. Formic acid ester and ethanol were subsequently distilled off at normal pressure (sump temperature up to 130.degree. C.). The residue was mixed with ether. Sodium carbonate was added to the solution and the product was washed neutral with water. The solvent was evaporated, and the residue was fractionally distilled under vacuum. 280 gm of 4-isopropyl-2,2,5,5-tetramethyl-1,3-dioxane having a b.p..sub.13 of 70.degree. C. were obtained, corresponding to a yield of 70% of theory.

The other 4-isopropyl-5,5-dimethyl-1,3-dioxane, whose odor characteristics and physical data are given in the following Table, were obtained in an analogous manner.

TABLE______________________________________ Boiling point/ PressureEx. Designation .degree.C/Torr n.sub.D.sup.20 Odor______________________________________1 4-isopropyl-5,5- 71/20 1.4390 Herbal, odor of dimethyl-1,3- borneol, camphor dioxane2 4-isopropyl-2,5,5- 55/5.0 1.4306 Minty, odor of trimethyl-1,3- camphor, menthol dioxane3 2-ethyl-4-iso- 32/0.05 1.4325 Sweet, woody, propyl-5,5- fruity, sassa- dimethyl- fras, aniseed 1,3-dioxane cedramber fragrance4 2,4-diisopropyl- 94/20 1.4335 Spicy, woody, 5,5-dimethyl- fruity 1,3-dioxane5 4-isopropyl-2,2, 70/13 1.4305 Fragrance of 5,5-tetramethyl- freshly sawn 1,3-dioxane wood6 2-ethyl-4-iso- 70/4.0 1.4375 Minty, leathery, propyl-2,5,5- oryclon fragrance trimethyl-1,30 dioxane7 2,2-diethyl-4- 103/17 1.4420 Nutty, lovage, isopropyl-5,5- plum-jam dimethyl-1,3- fragrance dioxane8 2-cyclopropyl- 98/3.0 1.4508 Jasmone fragrance 4-isopropyl-2,5, 5-trimethyl-1,3- dioxane______________________________________

All the compounds given in the above Examples have the described fragrances which render them suitable for producing a wide variety of perfumery compositions. Such compositions can be used to perfume a wide variety of products such as cosmetics, washing agents, soaps as well as technical products in concentrations of approximately 0.05% to 2% by weight. Examples of perfumery compositions having a content of the 4-isopropyl-5,5-dimethyl-1,3-dioxanes in accordance with the invention are given hereinafter.

EXAMPLE 9

______________________________________Fantasy Lavender______________________________________4-isopropyl-5,5-dimethyl-1,3-dioxane 500 parts by weightExample 1Terpineol 100 parts by weightLavendine oil Abrialis 100 parts by weightLinalyl acetate 100 parts by weightLinalool 50 parts by weightKetone Musk 40 parts by weightLavender oil 30 parts by weightCumarin 20 parts by weightSandalwood manufactured by theFirm Haarmann & Reimer 20 parts by weightPatchouli oil Sing. 20 parts by weightCamphor 15 parts by weightAmbroxan, 10% in isopropyl myristate 5 parts by weight 1000 parts by weight______________________________________

EXAMPLE 10

______________________________________Conifer composition______________________________________4-isopropyl-2,2,5,5-tetramethyl-1,3-dioxane, Example 5 500 parts by weightPine needle oil, Siberian 200 parts by weightDwarf-pine oil 100 parts by weightBergamot oil 50 parts by weightLavandine oil 50 parts by weightCypress oil 20 parts by weightEucalyptus oil 20 parts by weightCedryl acetate 20 parts by weightHydroxycitronellal-dimethylacetal 20 parts by weightOak moss, absolute 50% 10 parts by weightRosemary oil 8 parts by weightLauric aldehyde 1 part by weight.beta., .gamma.-hexanol 1 part by weight 1000 parts by weight______________________________________

EXAMPLE 11

______________________________________Fantasy Jasmine______________________________________2-cyclopropyl-4-isopropyl-2,5,5-tri-methyl-1,3-dioxane, Example 8 120 parts by weightBenzyl acetate 455 parts by weightPhenylethyl alcohol 220 parts by weightGeraniol from citronella oil 58 parts by weightCinnamic alcohol 35 parts by weightCedar wood oil, Virginia 30 parts by weightBenzyl salicylate 25 parts by weightYlang-ylang oil 20 parts by weightMethyl anthranilate 20 parts by weightCananga oil 10 parts by weightIsoeugenol 5 parts by weightEthyl salicylate 2 parts by weight 1000 parts by weight______________________________________

The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, however, that other expedients known to those skilled in the art or disclosed herein, may be employed without departing from the spirit of the invention or the scope of the appended claims.

Claims

1. 2-cyclopropyl-4-isopropyl-2,5,5-trimethyl-1,3-dioxane.