Perfume composition

The perfume composition containing 4- (or 5-)-acyl-1,1- (or 3,3-)-[a] compound, which is a novel compound expressed by the formula I, has noble musk fragrance. In addition, this perfume composition has characteristics that it is excellent in both quality and strength of the fragrance, of high safety and capable of being manufactured with low costs.

FIELD OF TECHNOLOGY 
This invention relates to a perfume composition or, more particularly, 
relates to a perfume composition containing a novel compound represented 
by the formula (I) given below [in the formula, R.sub.1 is a methyl or 
ethyl group and either one of R.sub.2 and R.sub.3 is a methyl group, the 
other being a hydrogen atom]. 
##STR1## 
This perfume composition can be used effectively in soaps, liquid scents, 
cosmetics, room aromatics, masking agents and the like. 
BACKGROUND TECHNOLOGY 
In view of the extreme expensiveness and unstable supply of natural musk 
obtained from a musk deer, works have been undertaken intensively from old 
times to develop compounds having musk-like tone of fragrance and a large 
number of compounds have been discovered including those belonging to the 
types of nitro-musks, indan musks, Tetralin musks, macrocyclic musks and 
the like. 
In recent years, however, several of these compounds have become banned for 
use in soaps, cosmetics and the like in respect of the safety concern. 
Therefore, it is desired to have advent of a compound having musk-like 
tone of fragrance but less problems in safety. As such a compound, 
compounds having a skeleton of cyclopentanaphthalene are known and 
disclosures are already given for 
##STR2## 
in German Pat. No. 2,114,216 and for 
##STR3## 
in Japanese Patent Publication 42-6491 while they are each not 
satisfactory in respect of the quality and strength of the fragrance 
although they have no problem in respect of safety. 
Accordingly, the object of the present invention is to provide a compound 
of musk-like fragrance having a skeleton of cyclopentanaphthalene with 
high safety, low costs for manufacturing and fragrance excellent in both 
of quality and strength. 
DISCLOSURE OF THE INVENTION 
In the course of the comparative investigations for the synthetic methods 
and fragrance characteristics of a large number of compounds having a 
skeleton of cyclopentanaphthalene, the inventors have arrived at a 
discovery that acylation of a mixture composed of 
1,1-dimethyl-2,3,5,6,7,8-hexahydro-1H-cyclopenta[b]-naphthalene (referred 
to as the 1,1-[b] compound hereinbelow), 
1,1-dimethyl-2,3,6,7,8,9-hexahydro-1H-cyclopenta[a]naphthalene (referred 
to as the 1,1-[a] compound hereinbelow) and 
3,3-dimethyl-1,2,6,7,8,9-hexahydro-1H-cyclopenta[a]naphthalene (referred 
to as the 3,3-[a] compound hereinbelow) produced by the cyclization 
reaction of Tetralin and isoprene gives a mixture composed of the 
4-acyl-1,1-[b] compound and 4-(or 5-)acyl-1,1-(or 3,3-)-[a] compound, 
which in itself has only ionone-like weak musk fragrance but is capable of 
giving a perfume composition having unexpectedly strong and noble musk 
fragrance by removing the 4-acyl-1,1-[b] compound, which is a known 
compound, by column chromatography and that the entity of the musk 
fragrance is the 4-(or 5-)acyl-1,1-(or 3,3-)-[a] compound, which is a 
novel compound, leading to completion of the present invention. 
Namely, the present invention relates to a perfume composition containing 
the 4-(or 5-)-acyl-1,1-(or 3,3-)-[a] compound represented by the formula 
##STR4## 
[in the formula, R.sub.1 is a methyl group or ethyl group and either one 
of R.sub.2 and R.sub.3 is a methyl group, the other being a hydrogen atom] 
.

THE BEST MODE TO PRACTICE THE INVENTION 
In order to obtain the perfume composition of the present invention, 
Tetralin is subjected to a cycloaddition of isoprene, as is shown by the 
following reaction equation, according to a known method (Japanese Patent 
Publication 42-6491, Japanese Patent Publication 60-20364, and others) to 
give a mixture composed of the 1,1-[b] compound, 1,1-[a] compound and 
3,3-[a] compound (they are produced in a proportion of approximately 
32:40:28) which is further acylated into a mixture of the 4-acyl-1,1-[b] 
compound the 4-(5-)-acyl-1,1-(or 3,3-)-[a] compound. (Note that the 
4-acyl-3,3-[a] compound is scarcely formed). 
##STR5## 
The mixture of the acylated compounds can be eluted by the silica gel 
column chromatography using a mixture of ethyl acetate and n-hexane (1:20) 
as the eluent in a sequential order of 4-acyl-1,1-[b] compound, 
5-acyl-3,3-[a] compound, 5-acyl-1,1-[a] compound and 4-acyl-1,1-[a] 
compound so that the perfume composition of the present invention can be 
obtained by removing the 4-acyl-1,1-[b] compound. 
In the present invention, the 4-(or 5-)-1,1-(or 3,3-)-[a] compounds can be 
used either as a mixture or singly after isolation into the individual 
compounds. When they are used after isolation, the 4-acyl-1,1-[a] compound 
is the best in both of the quality and strength as a musk fragrance and 
next comes the 5-acyl-3,3-[a] compound. 
Further, the R.sub.1 in the acyl groups should preferably be a methyl group 
or an ethyl group as a musk fragrance and propyl group and higher groups 
are undesirable due to the ionone-like tone as the musk fragrance. 
The perfume composition of the present invention obtained in this manner 
can be used effectively in soaps, perfumes, cosmetics, airfreshners, 
masking agents and the like as a safe and high-quality perfume base having 
musk fragrance and serves to improve and strengthen the fragrance of these 
products imparting an increased commercial value thereto. 
The added amount of the compound represented by the formula [I] in the 
present invention should be adequately selected in consideration of the 
object of use and other factors and the added amount in the final product 
is usually from 0.001 to 10% by weight or, preferably, from 0.01 to 1% by 
weight. And, it is optional that the perfume composition of the present 
invention is admixed with conventional auxiliary ingredients such as 
solvents, surface active agents, germicides, coloring agents and the like. 
In the following, the present invention is described in more detail by way 
of Examples and Reference Examples. 
PREATORY EXAMPLE 1 
Preparation of cyclized mixture. 
290 g of Tetralin were admixed with 300 g of a 93% sulfuric acid and 
chilled at -5.degree. C. A solution prepared by dissolving 61.2 g (0.9M) 
of isoprene in 290 g of Tetralin was added dropwise thereto at -5.degree. 
to 0.degree. C. under vigorous agitation over a period of 4 hours. After 
completion of the dropwise addition, agitation was further continued for 
additional 1 hour at the same temperature followed by phase separation of 
the oily layer separated by standing. 
The oily layer was successively washed with water, a 5% sodium hydroxide 
solution and a 5% sodium hydrogen carbonate solution followed by drying 
with anhydrous sodium sulfate. After removing the unreacted Tetralin by 
distillation, distillation was performed and the fraction boiling at 
89.degree. to 98.degree. C. under 0.3 mmHg was collected to give the 
cyclized mixture. The yield was 100 g (55.5% of the theoretical yield) and 
the characteristic parameters were d.sub.20.sup.20 =0.978 and 
n.sub.D.sup.20 =1.545. 
This mixture was identified from the results of the gas chromatographic 
analysis to be composed of the 1,1-[b] compound, 1,1-[a] compound and 
3,3-[a] compound approximately in a proportion of 32:40:28. 
PREATORY EXAMPLE 2 
Preparation of acetylated mixture. 
50 g of 1,2-dichloroethane are admixed with 31.2 g of aluminum chloride and 
21.2 g (0.27M) of acetyl chloride are added thereto dropwise at room 
temperature over a period of 15 minutes. A solution prepared by dissolving 
36.5 g (0.18M) of the mixture obtained in Preparatory Example 1 in 25 g of 
1,2-dichloroethane was added thereto dropwise under agitation at room 
temperature over a period of 30 minutes. After completion of the dropwise 
addition, agitation was further continued for additional 1 hour and then 
it was poured into ice water to decompose the catalyst followed by phase 
separation to take the separated oily layer. 
The oily layer was successively washed with water, a 5% sodium hydroxide 
solution and water followed by drying with anhydrous sodium sulfate. After 
removing the dichloroethane by distillation, distillation was performed 
and a fraction boiling at 140.degree. to 142.degree. C. under 0.2 mmHg was 
collected to give the acetylated mixture. The yield of the thus obtained 
mixture was 36.3 g (82.0% of the theoretical yield) and the characteristic 
parameters were d.sub.20.sup.20;b =1.047 and n.sub.D.sup.20 =1.557. 
This mixture was identified from the results of the gas chromatographic 
analysis to be composed of the 4-acetyl-1,1-[b] compound, 5-acetyl-3,3-[a] 
compound, 5-acetyl-1,1-[a] compound and 4-acetyl-1,1-[a] compound formed 
approximately in a proportion of 27:29:20:24. 
The chromatogram is illustrated in FIG. 1. 
PREATORY EXAMPLE 3 
Preparation of propionylated mixture. 
The reaction was performed in the same manner as in Preparatory Example 2 
excepting the use of 25 g (0.27M) of propionyl chloride in place of the 
acetyl chloride in Preparatory Example 2 and the fraction boiling at 
147.degree. to 150.degree. C. under 0.1 mmHg was collected by distillation 
to give 38.1 g (82.6% of the theoretical yield) of the propionylated 
mixture. 
PREATORY EXAMPLE 4 
Preparation of perfume composition and isolation of the individual 
ingredients. 
25 g of the acetylated mixture obtained in Preparatory Example 2 were 
dissolved in 50 ml of n-hexane and column chromatography was performed 
using a silica gel as the stationary phase (6 cm.times.120 cm) and ethyl 
acetate:n-hexane (1:20) as the eluent. 
Since the acetylated mixture was eluted out in the sequential order of the 
4-acetyl-1,1-[b] compound, 5-acetyl-3,3-[a] compound, 5-acetyl-1,1-[a] 
compound and 4-acetyl-1,1-[a] compound, a perfume composition could be 
obtained by removing the 4-acetyl-1,1-[b] compound from the acetylated 
mixture. Further, each of the individual ingredients was isolated by the 
second chromatography of the respective fraction rich in the content of 
the ingredient. 
Each of the ingredients as a novel compound has characteristic parameters 
shown below. 
5-Acetyl-3,3-[a] compound: d.sub.20.sup.20 =1.046; n.sub.D.sup.20 =1.556; 
IR (liquid film on NaCl, cm.sup.-1) 1680 (C.dbd.O) (shown in FIG. 2); 
NMR (CDCl.sub.3, ppm) 1.27 (6H: 3,3-di-CH.sub.3), 2.56 (3H: acetyl 
CH.sub.3), 7.24 (H: 4-H), (shown in FIG. 3) 
5-Acetyl-1,1-[a] compound: d.sub.20.sup.20 =1.047; n.sub.D.sup.20 =1.557; 
IR (liquid film on NaCl, cm.sup.-1) 1680 (C.dbd.O) (shown in FIG. 4); 
NMR (CDCl.sub.3, ppm) 1.35 (6H: 1,1-di-CH.sub.3), 2.53 (3H: acetyl 
CH.sub.3), 7.26 (H: 4-H), (shown in FIG. 5) 
4-Acetyl-1,1-[a] compound: d.sub.20.sup.20 =1.047; n.sub.D.sup.20 =1.557; 
IR (liquid film on NaCl, cm.sup.-1) 1675 (C.dbd.O) (shown in FIG. 6); 
NMR (CDCl.sub.3, ppm) 1.33 (6H: 1,1-di-CH.sub.3), 2.54 (3H: acetyl 
CH.sub.3), 7.42 (H: 5-H), (shown in FIG. 7) 
PREATORY EXAMPLE 5 
Isolation of the individual ingredients from the propionylated mixture. 
In the same manner as in Preparatory Example 4 excepting the use of the 
propionylated mixture obtained in Preparatory Example 3 in place of the 
acetylated mixture in Preparatory Example 4, the individual ingredients of 
the 4-propionyl-1,1-[b] compound, 5-propionyl-3,3-[a] compound, 
5-propionyl-1,1-[a] compound and 4-propionyl-1,1-[a] compound were 
isolated. 
REFERENCE EXAMPLE 1 
Evaluation of fragrance. 
Evaluation of fragrance was performed of the acetylated mixture obtained in 
Preparatory Example 2 and each of the ingredients obtained in Preparatory 
Example 4 by three expert perfumers. The result are shown in Table 1. 
TABLE 1 
______________________________________ 
Threshold 
Sample value Odor character 
______________________________________ 
Control 
Acetylated mixture 
1/500 Ionone-like weak 
musk fragrance 
Control 
4-Acetyl-1,1-[b] 
1/500 Ionone-like weak 
compound musk fragrance 
Present 
5-Acetyl-3,3-[a] 
1/10000 Somewhat strong 
invention 
compound nitro musk 
fragrance 
Present 
5-Acetyl-1,1-[a] 
1/1000 Weak musk 
invention 
compound fragrance 
Present 
4-Acetyl-1,1-[a] 
1/100000 Noble and strong 
invention 
compound musk fragrance 
______________________________________ 
As is clear from Table 1, the 4-acetyl-1,1-[a] compound had the highest 
quality as well as highest strength of the fragrance and the strength 
thereof was about 200 times of that of the acetylated mixture. 
EXAMPLE 1 
Application to perfume. 
A perfume described below was prepared respectively using the perfume 
composition obtained in Preparatory Example 4. 
Perfume for sandalwood tone 
______________________________________ 
Ingredient Parts by weight 
______________________________________ 
Lavandin oil 110 
Anisaldehyde 5 
Amyl salicylate 30 
Geranium oil 45 
Cinnamic aldehyde 10 
Coumarin 90 
Santalex 300 
Patchouli oil 60 
Perfume composiion obtained in 
350 
Preparatory Example 4 
1000 
______________________________________ 
The above described formulation gave a perfume for sandalwood tone having a 
noble musk tone. The fragrance thereof was greatly improved in comparison 
with the perfume formulated with the acetylated mixture obtained in 
Preparatory Example 2 in place of the perfume composition in the above 
described formulation. 
EXAMPLE 2 
A perfume described below was prepared by using the 4-acetyl-1,1-[a] 
compound obtained in Preparatory Example 4. 
Perfume for okamoss tone 
______________________________________ 
Ingredient Parts by weight 
______________________________________ 
.alpha.-Amyl cinnamaldehyde 
110 
Methyl anthranilate 10 
Eugenol 40 
Aurantiol(Methyl N--3,7-dimethyl-7- 
10 
hydroxyoctyliden anthranilate) 
Phenethyl alcohol 22 
Benzyl acetate 70 
Terpinyl acetate 70 
Verbenone(p-t-Butyl cyclohexyl acetate) 
150 
Dihydromyrcenol 7 
p-Cresyl methyl ether 6 
Eucalyptus oil 30 
Lavandin oil 200 
Coumarin 45 
Patchouli oil 50 
Lilial(p-t-Butyl-.alpha.-methyl hydro cinnamic 
35 
aldehyde) 
4-Acetyl-1,1-[a] compound obtained 
in Preparatory Example 4 
145 
1000 
______________________________________ 
The above described formulation gave a perfume for chic and deep oakmoss 
tone. The fragrance thereof was greatly improved in comparison with the 
perfume formulated with the acetylated mixture obtained in Preparatory 
Example 2 in place of the 4-acetyl-1,1-[a] compound in the above described 
formulation. 
REFERENCE EXAMPLE 2 
Five kinds of the novel compounds obtained in Preparatory Examples 4 and 5 
were subjected to the test of primary irritation by open patch, test of 
photo-toxicity by the Morikawa method and test of sensitizability by the 
Magnason method using guinea pigs with the hairs shaved off. The results 
are shown in Table 2. 
TABLE 2 
______________________________________ 
Primary irri- 
Photo- 
tation toxicity Sensitization 
(24 hours) 
(24 hours) 
(48 hours) 
Concentration 
Sample 10% 5% 10% 5% 10% 5% 
______________________________________ 
4-Acetyl-1,1-[a] 
-- -- -- -- -- -- 
compound 
5-Acetyl-1,1-[a] 
-- -- -- -- -- -- 
compound 
5-Acetyl-3,3-[a] 
-- -- -- -- -- -- 
compound 
4-Propionyl-1,1-[a] 
-- -- -- -- -- -- 
compound 
5-Propionyl-3,3-[a] 
-- -- -- -- -- -- 
compound 
______________________________________ 
(Solvent: acetone; application dose: 0.02 ml) 
All of the samples exhibited absolutely no irritation and sensitization to 
the animal skin to give confirmation that the novel compounds of the 
present invention were of high safety. 
USE IN INDUSTRY 
The perfume composition of the present invention has excellent musk 
fragrance and is a material of high safety. Accordingly, it is used as a 
perfume base in soaps, perfumes, cosmetic preparations, airfreshners, 
masking agents and the like.