JPH0558930A - 2-(1-hydroxy-isopropyl)-5-methyl-cylopentanol - Google Patents

Abstract

PURPOSE:To obtain new 2-(1-hydroxy-isopropyl)-5-methyl-cyclopentanol having excellent effects as a repellent against harmful organisms, improved durability of effects and no peculiar smell. CONSTITUTION:2-(1-Hydroxy-isopropyl)-5-methyl-cyclopentanol shown by the formula. The compound is obtained by blending 2,6-dimethyl-5-heptenal with an aqueous solution of an acid such as sulfuric acid while stirring. The compound is a pale yellow oily substance hardly having a smell and is taken out as crystals by subjecting the compound to column treatment and isolating as the cis-isomer and the trans-isomer. The isomers have excellent repelling effects on harmful organisms such as mosquitoes. A base for cosmetic or medicine is mixed with preferably 0.1-90%, preferably 3-20% of the compound to give various agent forms of repellents against harmful organisms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel compound which is substantially odorless in itself and has an extremely long-lasting effect as a pest repellent.

[0002]

Conventionally, N, N-diethyltoluamide has been widely used as a pest repellent for protecting oneself from pests such as mosquitoes.
However, since this N, N-diethyltoluamide has a problem that it has a peculiar odor, the development of a new pest repellent has been desired. The present invention has been made in view of such circumstances, and an object thereof is to provide a novel compound having an excellent pest repellent effect, having no peculiar odor, and having a sustained effect. It is in.

[0003]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have succeeded in synthesizing a novel compound, and this compound has an excellent pest repellent effect and its persistence. Have been found. That is, the novel compound of the present invention has the following structural formula

[Chemical 2] 2- (1-hydroxy-isopropyl) -5 represented by
-Methyl-cyclopentanol.

The details of the configuration of the present invention will be described below. 2- (1-hydroxy-isopropyl) -of the present invention
5-Methyl-cyclopentanol can be obtained by mixing 2,6-dimethyl-5-heptenal with an aqueous acid solution such as sulfuric acid and stirring. 2- (1-hydroxy-isopropyl) -5-methyl-obtained in this way
Cyclopentanol is a pale yellow oil with almost no odor.

Then, the oily substance can be subjected to a column treatment or the like to isolate the cis form and the trans form, whereby the oily substance can be taken out as crystals. This 2- (1-hydroxy-isopropyl) -5-methyl-cyclopentanol has an excellent repellent effect against pests such as mosquitoes in both cis and trans forms.

By incorporating 2- (1-hydroxy-isopropyl) -5-methyl-cyclopentanol of the present invention as a useful ingredient into a base of cosmetics or pharmaceuticals which is usually used, various compounds can be prepared. It is possible to obtain pest repellents in dosage form. The content of the compound varies depending on the formulation form, method of use, and other conditions, but the content is generally 0.1% to 90%, and particularly 3% to 20%. preferable.

The thus-obtained compound of the present invention is used for pests such as mosquitoes such as Aedes albopictus, millipedes, millet and slugs.

[0008]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, unless otherwise specified, the% display in the following means% by weight.

Example 1 2,6-Dimethyl-5-heptenal (melona)
50 g of 20% sulfuric acid aqueous solution 300 g
After slowly adding the mixture therein, the mixture was vigorously mixed and stirred for 20 hours, and the reaction solution was extracted with 150 ml of diethyl ether. Then, the diethyl ether layer was washed twice with 100 ml of a 10% sodium carbonate aqueous solution and then twice with 100 ml of saturated saline.

The diethyl ether layer was dried over anhydrous sodium carbonate and the diethyl ether was removed to obtain a crude reaction product. Further, the crude reaction product was produced by silica gel column chromatography (developing solvent hexane / ethyl acetate = 4/1) to obtain 35 g (yield 62%) of a pale yellow oily substance.

In the mass spectrum measurement of the obtained oily substance, a peak of [parent peak molecular weight] -15 (derived from methyl group) was observed, and in elemental analysis, C = 68.24.
%, H = 11.58% measured value (theoretical value of C and H is C =
68.31%, H = 11.47%). Furthermore, by measuring the infrared absorption spectrum, 2,6-
Absorption at 1740 cm ^-1 derived from the aldehyde group of dimethyl-5-heptanal disappeared, and 3400 cm ^-1 and 1
Absorption of hydroxyl groups was confirmed at 180 cm ^-1 . In addition, the absorption due to the ring structure is 1480 cm ^-1 , 1040 cm
Absorption was confirmed at ^-1 , 940 cm ^-1 . As a result, 2-
Formation of (1-hydroxy-isopropyl) -5-methyl-cyclopentanol was confirmed.

The application examples of the present invention are shown below. Application Examples 1 and 2 and Comparative Examples 1 and 2 [Liper Lotion] According to the composition of Table 1 below, Application Examples 1 and 2 and Comparative Example 1,
The repellent lotion of 2 was prepared and the following pest repellent test was conducted. Incidentally, N, N-diethyltoluamide has been conventionally used as a pest repellent.

[0013]

[Table 1]

Pest repellent test (1) Test method of pest repellent effect and its effect persistence In order to examine repellent effect of Aedes albopictus on adults,
The following tests were conducted in a thermostatic chamber at room temperature of 30 ° C. and humidity of 70%. After 10 ml of each test sample was applied to the left and right forearms, each arm was inserted into a bag-shaped 20 cm × 15 cm wire net containing 50 adult male and female Aedes albopictus 5 to 7 days after emergence for 15 minutes, and blood was absorbed. I gave you time.
This treatment was performed after 30 minutes, 1 hour, 2 hours, 4 hours, and 6 hours, the number of blood-sucking traces within the blood-sucking time was determined, and the repellency rate was calculated from the following formula.

[Equation 1] X: Number of blood-sucking traces when test liquid was not applied Y: Number of blood-sucking traces when test liquid was applied

(2) Results For the application examples 1 and 2 and the comparative examples 1 and 2, a blood-sucking repellent test was conducted on the adult Aedes albopictus. The results are shown in Table 2. As is clear from Table 2, 2 of the present invention
-(1-Hydroxy-isopropyl) -5-methyl-cyclopentanol had an excellent pest repellent effect and its persistence.

[0016]

[Table 2]

[0017]

INDUSTRIAL APPLICABILITY As described above, the present invention provides 2- (1-hydroxy-isopropyl) -5-methyl-cyclopentanol having an excellent effect and durability as a pest repellent. is there.

Claims (1)

[Claims] 1. The following general structural formula: 2- (1-hydroxy-isopropyl) -5 represented by
-Methyl-cyclopentanol.