JPS5842175B2 - 2-Alkyl-cyclopentenone - Google Patents

Description

Detailed Description of the Invention The present invention is based on the following formula (1), where R1 represents a hydrogen atom or a methyl group, R2 represents a linear or branched C1-CIO saturated alkyl group, or R2 is 1'- in the formula to which it is bonded.
2-alkyl-cyclobentenone, which is useful as a jasmine fragrance substance and which together with the carbon atom at the C3 or C6 alicyclic saturated alkyl group is represented by the following formula (2), where the formula 2-alkylidene-cyclopentanone color, in which R1 and R2 have the same meanings as above, can be produced in high yield and with easy operation, and also avoids disadvantageous elimination from the viewpoint of pollution in conventional proposals. The present invention relates to a method for producing the compound of formula (1) by an advantageous method that does not involve the production of liquid as a by-product.

Conventionally, as a method for producing a compound included in the formula (1) by converting a compound in which R1 is hydrogen in the formula (2), a method for producing a compound included in the formula (1) has been carried out at about 100° C. using a polyhydric acid as a catalyst.
There is a known proposal to perform an isomerization reaction by heating at a temperature of (Tetrahedron Let-ters: V
o125, 6025.1959).

According to this proposal, the desired isomerized product can only be obtained with a yield of about 10% at most.

In addition, a large amount of by-products are produced, making it difficult to employ industrially.

Furthermore, this method is disadvantageous from the standpoint of pollution because wastewater containing polyhydric acid is produced and requires treatment.

Furthermore, as another proposal, R1 included in the above formula (2)
It has been reported that for a compound in which R is a hydrogen atom and R2 is a methyl, the desired isomerized product was obtained in a yield of 53% using a method similar to the above proposal (Bull.

Soc, Chem, France; 2972 pages, 1970Q In addition to the low yield in this proposal,
This method is also disadvantageous in that it produces up to 47% of by-products, is difficult to employ industrially, and involves inconvenient drainage.

As a result of research into a method that can industrially advantageously carry out this isomerization reaction, the present inventors have discovered that a metal catalyst of the metal group No. The term "metal catalyst" does not include metal compound catalysts such as metal salts or complexes).
By heating alkylidenecyclopentanone,
It has been discovered that 2-alkyl-cyclobentenone of the formula (1) can be produced in high yield with an excellent selectivity that cannot be achieved with conventional proposals, with easy operation, and without drainage that causes pollution. did.

Therefore, an object of the present invention is to provide a method for producing the 2-alkylcyclobentenone of formula (1) industrially and advantageously.

The above objects and many other objects and advantages of the present invention include:
The following description will make it even clearer.

Specific examples of the C0-CIO saturated alkyl group or the C5-C6 alicyclic saturated alkyl group of the 2-alkylidene-cyclopentanone represented by the formula (2) in the method of the present invention include, for example, CH3- 2CH3CH2-
2CH3CH2CH2-CH3(CH2) 2CH2
, CH3(CH2)s CR2CR3(CH2)4CH
2-2CH3(CH2)5CH2,CR3(CR2)
6 CR2-CR3(CR2) 7CH2 and CH3(
C1-C1o straight chain saturated alkyl groups such as CH2)8CH2-; e.g. (CH3)2CH-2(CH3)2CH-CH2CH3
CH2CH(CH3)-2(CH3)2CHCH2CH
2-2CH3CH2CH(C2H5)-2 and CH3C
C2~ like (CH3)2CH2CH(CH3)CH2
C1o branched saturated alkyl group; and cyclopentyl,
Mention may be made of C5-C6 alicyclic saturated alkyl groups such as cyclohexyl.

Specific examples of such compounds of formula (2) include, for example, 2-ethylidene-cyclopentanone, 2-iso) propylidene-cyclopentanone, 2-n-7') pylidene-cyclopenquone, and 2-isobutylidene. -Cyclopentanone, 2-n-butylidene-cyclopencnone, 3-methyl-2-isobutylidene-cyclopentanone, 3-methyl-2-n-7'tylidene-cyclopencnone, 2-inpentylidene -cyclopentanone, 2
-n-pentylidenecyclopentanone, 2-(2'-methyl-butylidene)-cyclopentanone, 3-methyl-
2-isopentylidene-cyclopentanone, 3-methyl-2-n-pentylidene-cyclopentanone 2-isohexylidene-cyclopentanone, 2-(2/-ethyl-butylidene)-cyclopentanone, 2- n-hexylidene-cyclopentanone 3-methyl-2-isohexylidene-cyclopentanone, 3-methyl-2-n-hexylidene-cyclopentanone, 2-n-hebutylidene-cyclopentanone, 2-n-ofthylidene- Cyclopentanone, 2-(2'-ethyl-hexylidene)-cyclopentanone, 2-n-nonylidene-cyclopentanone, 2
-(3'-Methyl-5',5'-dimethyl-hexylidene)-cyclopentanone, 2-n-decylidene-cyclopentanone, 2-n-undecylidene-cyclopentanone, 2-cyclopentyl Lyden-cyclopentanone and 2
- such as cyclohexylidene-cyclopentanone, 2-
Alkylidene-cyclopentanone can be exemplified.

Further, as the 2-alkylcyclobentenone represented by the formula (1), for example, 2-ethylcyclopetethinone, 2-isopropyl-cyclobentenone, 2-n-propyl-cyclobentenone, 2-imbutyl -cyclobentenone, 2-n-butyl-cyclobentenone 3-methyl-2-isobutyl-cyclobentenone, 3-methyl-2-n-butyl-cyclobentenone, 2-inbenten-cyclobentenone, 2-
n-pentyl-cyclobentenone, 2-(2'-methylbutyl)-cyclobentenone, 3-methyl-2inpentyl-cyclobentenone, 3-methyl 2- n-pentyl-cyclobentenone, 2-isohexyl- Cyclobentenone, 2-(2'-ethyl-butyl)-cyclobentenone, 2-n-hexyl-cyclobentenone, 3-methyl-2-isohexyl-cyclobentenone, 3-methyl-2n-hexyl-cyclo Bentenone, 2-n-hephthyl-cyclopentenone, 2-n-octyl-cyclobentenone, 2-(2/-ethyl-hexyl)cyclobentenone, 2-n-nonyl-cyclobentenone, 2-( 3'
-Methyl-5',5'-dimethylhexyl)-cyclobentenone, 2-n-decyl-cyclobentenone, 2-n
Mention may be made of 2-alkyl-cyclobentenones such as -undecyl-cyclobentenone, 2-cyclopentyl-cyclobentenone and 2-cyclohexyl-cyclobentenone.

According to the method of the present invention, by heating the exemplified 2-alkylidene-cyclopentanone represented by the formula (2) in the presence of a metal catalyst of the metal group No. 1 of the periodic table, 2-alkyl-cyclobentenone, which is useful as a jasmine-based fragrance substance represented by formula (1) as exemplified above, can be isomerized easily and with excellent selectivity.

The reaction can be carried out in the presence or absence of a solvent.

As the solvent, a wide variety of inert organic solvents can be used, such as alcohols, ketones, ethers, esters, hydrocarbons, and mixtures of arbitrary combinations thereof.

Since the platinum group metal catalyst used in the present invention is not substantially dissolved in these inert organic solvents, the reaction in the method of the present invention is carried out in a heterogeneous system.

Specific examples of such solvents include methanol, ethanol, propatool, impropatol, isobutanol, tertiary butanol, n-butanol, 2-butanol,
Straight chain, branched or Alicyclic alcohols, and glycols having a carbon number of C2 to C4, such as ethylene glycol, propylene glycol, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monoethyl ether, diethylene glycol, and diethylene glycol monomethyl ether. and its derivatives, as well as alcohols such as benzyl alcohol and phenylethanol;
For example, methyl butyl ketone, methyl isopropyl ketone, methyl propyl ketone, methyl isobutyl ketone, methyl n-butyl ketone, methyl n-amyl ketone,
Ketones such as methyl isoamyl ketone, ethyl butyl ketone, methyl n-hexyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone and cyclohexanone; for example, isopropyl ether, n-butyl ether, isoamyl ether, n-hexyl ether, 1, Ethers such as 4-dioxane, tetrahydropyran 2-methylfuran, diethylene glycol diethyl ether, methyl phenyl ether and ethylphenyl ether; for example n-butyl formate, methyl acetate, isopropyl acetate, n-butyl acetate, n-acetate Amyl, n-hexyl acetate, cyclohexyl acetate, ethyl propionate, n-butyl propionate, methyl butyrate, n-butyl butyrate, methyl isovalerate, ethyl lactate, methyl benzoate, propyl benzoate, dimethyl phthalate , diethyl oxalate, dimethyl succinate, dimethyl glutarate and dimethyl adipate; and esters such as n-hexane, n-octane, n-decane,
Hydrocarbons such as refloin, cyclohexane, benzene, toluene, xylene, ethylbenzene, isopropylbenzene, amylbenzene, t-butylbenzene, p-cymene, tetralin and decalin; and any mixtures thereof may be exemplified.

The use of a solvent often helps to further improve the yield of the target compound of formula (1) and gives favorable results.

There are no particular restrictions on the amount used, but usually the formula (
2) It is used in an amount of about 5 to about 500 wt% based on the compound.

The reaction is preferably carried out in the substantial absence of molecular oxygen, and if desired, an inert gas such as nitrogen, helium, argon, carbon dioxide, etc. can be used to perform the reaction in the presence of these inert gases. can be done.

Furthermore, the reaction can be carried out in the presence of a reducing gas such as hydrogen gas.

Carrying out the reaction under such a reducing atmosphere allows lower reaction temperatures to be employed and also tends to improve the reaction rate, and furthermore, the catalyst can be combined with metal compounds such as oxides,
They often give better results, with benefits such as being able to be used in the form of hydroxides and the like.

In the method of the present invention, metals from group Ⅰ of the periodic table, Os, P
The thermal isomerization reaction is carried out in the presence of a Group I platinum group metal catalyst selected from the group consisting of U, Ir, Rh, Pt and Pd.

These metals can be used alone or in combination, but for example, when used alone, it is preferable to use Pi or Pd.

When used in combination, these metals are preferably used in combination with other metals listed above.

The selection of these metal catalysts is based on the use of the inert organic solvent,
It can also be changed appropriately by combining with other conditions such as employing a reducing atmosphere.

These Group I metal catalysts of the periodic table may contain secondary amounts of other metal components or co-catalysts.

Examples of such other metal components include, for example, Ti
, V, Cr, Mn, Fe, Co, Ni, Cu, W.

Examples include Ag and Au.

Further, the catalytic metal can be supported on a carrier,
For example, carbon, alumina, silica, alumina silica,
Examples include barium sulfate and calcium carbonate.

The amount of the catalyst to be used varies depending on other reaction conditions, the type of catalyst, etc., and can be selected appropriately. An example is quantity.

More or less amounts may be used if desired.

Particularly preferably about 0.1 to about 10 wt%.

The reaction may be carried out at any temperature as long as isomerization occurs, and there are no particular restrictions, but temperatures of about 80 to about 300°C can be exemplified.

Preferably, the temperature is about 100 to about 250°C.

The reaction temperature can also be appropriately selected depending on the type of catalyst, reaction format, other reaction conditions, etc.

The reaction time can also be set appropriately.

Usually, it is about 5 minutes to about 12 hours.

The reaction can be carried out in either a liquid phase or a gas phase, and can be carried out either batchwise or continuously.

The reaction can be carried out under atmospheric pressure conditions, in particular without employing elevated or reduced pressure conditions, although, of course, elevated or reduced pressure conditions can also be employed.

For example, 760mwHf!・Less than gauge, about 10 to about 75
Reduced pressure conditions such as 0mmH&, e.g. 760mwHg gauge or higher, e.g. 76011LrILH9-100kg
/c1? An example of this is pressurization conditions such as L gauge.

According to the method of the present invention, as described in detail above, simply by heating the raw material formula (2) 2-alkylidene-cyclopentanone in the presence of a metal group metal catalyst of flag 1 of the periodic table. Desired isomerization can be carried out, and 2-alkyl-cyclobentenone of formula (1) can be obtained in good yield and selectivity.

Next, several examples of implementing the method of the present invention will be explained in more detail by way of examples.

Example 1 30.0 g of 2-n-hexylidene-cyclopentanone
(0.18 mol), n-hexanol 7.5 g (25
wt related raw material) and 5φpt-carbon 0.3g (1,
% of raw material) to the flask.

The mixture is stirred at 180-185° C. for 6.0 hours under nitrogen flow.

After the reaction is complete, the mixture is filtered and the catalyst is removed using Improper Tools 3.0. ! Wash at step 9.

The combined filtrate is fractionally distilled to obtain 27.8 g of 2-n-hexyl-cyclobentenone.

bP・115～12o0C/10℃Hg, purity 99.9
Steamed rice, yield 92.7 yen, carbonyl value 336.7 (theoretical value 337.4), d 80.921, n 1.472
Structural analysis of the 3° product was confirmed by instrumental analysis and identification with the standard.

The results of the instrumental analysis are as follows.

■R(cIrL-ri; 3043(J/=CH,W
) tl 702 (ν>C=O,v-s) tl 630 (ν>C=C< , m) NMR (δ1ncDc13); 0.89 (3Ht C
Hs; t, J=5 cps), 1.1-1.6
(8H, m), 2.0-2.6 (6H.

m), 7.2 (LH, m) U■；λ1 Tanoh"228mμ(emax=a 9880) MS (m/e): 166 (24%, molecular io→.

137 (27 buns), 123 (28φ)', 109 (32 many).

97 (93%), 96 (100 units), 81 (22φ), 41 (52%) Examples 2 to 24 Catalyst, solvent, and other reaction conditions were changed as shown in Table 1 below. was carried out in the same manner as in Example 1.

The results of Examples 2 to 24 are shown together with the results of Example 1 in Table 1.

Example 25 60 g of 2-n-hentylidene-cyclopestanone (
0,394 mol) and 501) Pt-carbon (1,0
wtφ vs. raw material) to the flask.

The mixture is heated to 130 DEG -5 DEG C. in a nitrogen stream, then hydrogen is blown in at a flow rate of 10 ml/mm (using a perforated jet tube) and stirred at the same temperature for 3.5 hours.

After the reaction is completed, the mixture is filtered, and the catalyst is washed with 6.0 g of Improper Tool and combined with the pre-p solution.

After recovering the solvent, simple distillation is performed to obtain 57.2 J of 2-n-pentyl-cyclobentenone.

bP, 107-112°C/10imH, 9, the composition ratio of this distillation section (GLC6a was as follows).

2-n-pentyl-cyclobentenone 93.0%, 2-
n-pentyl-cyclopentanone 5.9%, unreacted raw material 1.0%, yield 88.7%.

Further, the distillate was rectified to obtain 2n-pentyl-cyclobentenone with a purity of 980% in a yield of 70%.

The physical and chemical constants and instrumental analysis results of this fraction are as follows.

d2o0.935, n 1.4730, carbonyl value 367, 6 (theoretical value 368.5) I R((11772-li; 3040(cH,
w), 1702 (ν>C=O, ν, 8), 1630 (ν>C=C<, m) NMR (δ1ncDc13); 0.89 (3H.

CH3, t, J=5 cps), 1.1 to 1.6 (6H, m), 2.0 to 2.6 (6H, m), 7.3 (I H, m) 228 m μ(e max=8
800) MS (m/ε): 152 (30%, molecular ion), 137 (13φ), 123 (36.5%), 109 (39.5%), 97 (64%), 96 (100%) , 67 (58.5%), 53 (33%), 41 (74%) Examples 26 to 42 Other than changing the raw materials, catalyst, solvent and other reaction conditions as shown in Table 2 below. , and carried out in the same manner as in Example 24.

The results of Examples 26 to 42 are shown together with the results of Example 25 in Tables 2 and 3.

Claims (1)

[Claims] 1 The following formula (2), where R1 represents a hydrogen atom or a methyl group, and R
2 represents a linear or branched C1-CIO saturated alkyl group, or R2 together with the 1'-position carbon atom to which it is bonded represents a C6 or C6 alicyclic saturated alkyl group. 2-alkylidene-, which represents a group
The following formula (1) is characterized in that cyclopentanone is heated in the presence of a metal catalyst of the metal group No. 1 of the periodic table. - Method for producing alkylcyclopentynones.