JP3190105B2 - Method for producing iodoalkynyl carbamate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing iodoalkynyl carbamate, which is useful as a fungicide in paints, leathers, fibers and the like.

[0002]

2. Description of the Related Art U.S. Pat. No. 3,923,870 discloses the following general formula (1).

[0003]

Embedded image [IC @ C- (CH ₂ ) _n -OCO
NH] _m R (1) wherein R is a substituted or unsubstituted alkyl, cycloalkyl, aryl or aralkyl having 1 to 20 carbon atoms and having m valency. And m and n are each an integer of 1 to 3), and a process for producing the same.

[0004] As a method for producing the compound, the following general formula (3)

[0005]

Embedded image HC≡C- (CH ₂ ) _n OH
(3) (wherein n is the same as described above), alkynol represented by the following general formula (4)

[0006]

Embedded image IC @ C- (CH ₂ ) _n OH
(4) (wherein n is the same as described above) to obtain an iodoalkynol represented by the following formula, and then convert the substance to the following general formula (5)

[0007]

Embedded image R (NCO) _m
(5) (wherein R and m are the same as described above).

As another method, JP-A-55-100,354 (European Patent No. 0014032) discloses that alkynol represented by the above general formula (3) is represented by the above general formula (5). Reaction with isocyanate, the following general formula (2)

[0009]

Embedded image [HC≡C- (CH ₂ ) _n -OCON
H] _m R (2) (wherein, R, m and n are the same as those described above) to obtain an alkynylcarbamate, followed by iodinating the substance with the following iodinating agent, General formula (1)
A method for obtaining the compound represented by the formula is disclosed.

However, the former method has a drawback that many of the intermediates, iodoalkynols, have strong foaming properties and weak explosive properties. In addition, iodination by iodine is accompanied by by-product of periodate in addition to iodoalkynol. This cannot be removed in the next step, but is contained in iodoalkynyl carbamate, which is the target, and lowers the purity of the target.

On the other hand, the latter method is superior to the former method in that almost no periodate is produced as a by-product. However, since sodium hypochlorite and an alkali metal iodide, or sodium hypochlorite, an alkali metal hydroxide and iodine are used as an iodinating agent, the following inconveniences occur.

In this case, sodium hypochlorite is generated during iodination as an oxidizing agent, or oxidizes iodine ions added as a raw material to iodine which is effective for iodination of alkynyl carbamate. When sodium hypochlorite is lacking as a component of the above-mentioned iodination agent, a large excess (at least 2 times the mol of alkynyl carbamate) of iodine is required.

On the other hand, at a relatively high temperature, for example, at 10 ° C. or higher, sodium hypochlorite converts iodine to hypoiodite ion and further to iodate ion as an oxidizing agent, or a chlorine compound as a chlorinating agent. And by-products.

As described above, the addition of sodium hypochlorite is indispensable for the effective use of the iodine component. However, sodium hypochlorite not only oxidizes iodine ions but also chlorinates or Since it may act as an oxidizing agent, it is necessary to react at a temperature lower than 10 ° C. Further, sodium hypochlorite is liable to be converted into sodium chlorate during storage, so that its purity may be reduced, which is problematic in terms of stability. Therefore, great care must be taken for the storage of sodium hypochlorite.

[0015]

DISCLOSURE OF THE INVENTION The present invention uses an iodinating agent which does not cause a decrease in purity during storage without using the above-mentioned oxidizing agent, and has a high selectivity, a high purity and a high yield. An object of the present invention is to provide a method for producing iodoalkynyl carbamate, which is useful as an industrial fungicide.

[0016]

Means for Solving the Problems The present inventors have made intensive studies on the above-mentioned problems, and as a result, the following general formula (2)

[0017]

Embedded image [HC≡C- (CH ₂ ) _n -OCON
H] _m R (2) wherein R has 1-20 carbon atoms and is m-valent, substituted or unsubstituted alkyl, cycloalkyl, aryl or aralkyl And m and n are each an integer of 1 to 3). In the case of iodinating the alkynyl carbamate represented by the formula (1), iodine monochloride is used in place of iodide or iodine requiring an oxidizing agent. It has been found that it is effective to use only the present invention, and the present invention has been completed.

That is, the following general formula (1)

[0019]

[IC≡C- (CH ₂ ) _n -OCON
H] _m R (1) (wherein, R, m and n are the same as those described above) when the alkynyl carbamate represented by the above general formula (2) is used. A method for producing iodoalkynyl carbamate, comprising iodination using iodine chloride. Hereinafter, the present invention will be described in detail.

The alkynyl carbamate of the general formula (2) as a raw material is represented by the following general formula (3)

[0021]

Embedded image HC≡C- (CH ₂ ) _n OH
(3) wherein alkynol represented by the formula (5) is represented by the following general formula (5):

[0022]

Embedded image R (NCO) _m
(5) (wherein, R and m are the same as those described above). This reaction can be carried out by a method well known in the urethane field (for example, Chemical Society of Japan,
Organic Synthesis, Vol. 19, No. 11, p. 775-789 (1961). ).

The alkynol of the general formula (3) includes 2-alkynol
And propyn-1-ol, 3-butyn-1-ol, 4-pentyn-1-ol and the like.

Specific examples of the isocyanate of the general formula (5) include, for example, methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, hexyl isocyanate, octyl isocyanate, dodecyl isocyanate, octadecyl isocyanate and the like. Alkyl isocyanates, and their various structural isomers; cycloalkyl isocyanates, such as cyclohexyl isocyanate; monocyclic aryl isocyanates, such as phenyl isocyanate, 4-chlorophenyl isocyanate, 3,
4-dichlorophenyl isocyanate, 2-nitrophenyl isocyanate, 3-nitrophenyl isocyanate, 4
-Nitrophenyl isocyanate; diisocyanate, for example, hexamethylene diisocyanate, methylenebisphenyl diisocyanate, tolylene diisocyanate and the like.

The iodination of the alkynyl carbamate obtained by the above-mentioned method is usually carried out by using iodine monochloride of the alkynyl carbamate in water or a mixed solvent of water and an organic solvent in the presence of a base. When the solubility of alkynyl carbamate in water is low, a mixed solvent in which not only water but also an organic solvent which does not separate into two layers from water is used. Examples of such organic solvents include methanol, ethanol and the like.

The concentration of alkynyl carbamate in water or a mixed solvent is preferably about 5 to 20% by weight. If it is less than 5% by weight, productivity is undesirably reduced. or
Even at 20% by weight or more, no remarkable improvement in productivity is observed.

The amount of iodine monochloride is usually 1.0 to 1.2 mol, preferably 1 mol, per mol of alkynyl carbamate.
Use 1.0 to 1.1 moles. If it is less than 1.0 mol, the alkynyl carbamate will not be completely converted, and if it is used in excess of 1.2 mol, no improvement in yield will be observed and it will not be effective.

Although iodine monochloride can be used without a solvent, it is preferable to use it after dissolving it in an aqueous solution of hydrochloric acid or an aqueous solution of an alkali metal chloride, for example, an aqueous solution of sodium chloride or potassium chloride. Iodine monochloride is stable in aqueous hydrochloric acid or aqueous alkali metal chloride,
This is because the purity (content rate) hardly decreases even during long-term storage. The entire amount of iodine monochloride can be added at the initial stage, but it is preferable to add iodine monochloride continuously to make the reaction mild, and the addition time may be within 2 hours.

As the base used in the reaction, an alkali metal hydroxide, an alkali metal carbonate or an alkali metal bicarbonate can be used. Specifically, lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate and the like can be mentioned. The amount of the base was 0.95 per mole of iodine monochloride.
Preferred is about 2.00 gram equivalents. If it is less than 0.95 gram equivalent, the productivity is undesirably reduced, and if it is more than 2.00 gram equivalent, no remarkable improvement in productivity is observed. These bases can be added as a solid, but can also be added as an aqueous solution.

Before adding the iodine monochloride, the base can be added in its entirety, but it is also possible to add the base continuously in accordance with the addition of the iodine monochloride. Reaction temperature is 10 ~
Maintain in the range of 40 ° C. While maintaining this temperature, after adding iodine monochloride, the reaction is further carried out at the same temperature.
If the temperature is lower than 10 ° C, the reaction time becomes too long, and
If the temperature exceeds ℃, the yield is undesirably reduced.

The reaction time varies depending on the reaction temperature, but is usually 1 to 4 hours. After completion of the reaction, the reaction solution is neutralized.
Next, when the reaction is carried out in a mixed solvent, the organic solvent such as methanol may be removed by concentration or the like, or may be left as it is. Thereafter, iodoalkynyl carbamate is extracted and isolated from the reaction mixture with an organic solvent such as toluene or the like which separates into two layers from water. The isolated iodoalkynyl carbamate can be obtained as crystals by removing an organic solvent such as toluene. On the other hand, it can be used as it is as a solution such as toluene.

[0032]

EXAMPLES The present invention will be described below in detail with reference to Examples, but "%" is based on weight unless otherwise specified. The melting point of the product was measured, and the purity analysis was performed by HPLC (High-P
erformance Liquid Chromatography).

Example 1 In a reactor (capacity: 200 ml, equipped with a condenser and a stirrer), 7.75 g of prop-1-yn-3-yl Nn-butylcarbamate was added.
(0.050 mol) and 80 g of methanol, and 8.3 g (equivalent to 0.073 mol) of a 35% aqueous sodium hydroxide solution are added. Cool and maintain the solution at 10 ° C while maintaining a 15% aqueous sodium chloride solution containing 28% iodine monochloride (equivalent to 0.053 moles).
30.5 g are added in 20 minutes. Further, the solution is reacted at 15 ° C. for 2 hours. Thereafter, the solution is neutralized with hydrochloric acid and extracted with 40 g of toluene.

Further, extraction is performed five times with toluene, and the toluene extract is dried over anhydrous magnesium sulfate. The toluene was removed by evaporation under reduced pressure to obtain 13.8 g of 1-iodoprop-1-yn-3-yl Nn-butylcarbamate.
The melting point of the product was 65 to 67 ° C, the yield was 98.3 mol%, and no impurities were detected by the purity analysis.

Example 2 In Example 1, the starting material was prepared as prop-1-yn-3-yl N-
1-Iodoprop-1-yn-3-yl N-n-dodecylcarbamate 1 was operated in exactly the same manner as in Example 1 except that the amount of n-dodecylcarbamate was changed to 13.35 g (0.050 mol).
9.0 g were obtained. The melting point of the product was 54 to 56 ° C, the yield was 96.5 mol%, and no impurities were detected by the purity analysis.

Example 3 In Example 1, the starting material was prepared as prop-1-yn-3-yl N-
15.0 g of 1-iodoprop-1-yn-3-yl N-cyclohexylcarbamate was obtained in exactly the same manner as in Example 1, except that the amount was changed to 19.05 g (0.050 mol) of cyclohexylcarbamate. The melting point of the product was 118-120 ° C, the yield was 97.5 mol%, and no impurities were detected by the purity analysis.

EXAMPLE 4 7.75 g of prop-1-yn-3-yl Nn-butylcarbamate was placed in a reactor (capacity: 200 ml, equipped with a condenser and a stirrer).
(0.050 mol) and 80 g of methanol. The solution
Cool and maintain at 10 ° C. while maintaining 28% iodine monochloride (0.053
30.5 g of a 15% aqueous sodium chloride solution and 25% aqueous sodium hydroxide solution are simultaneously added over 20 minutes to maintain the pH at 7. In addition, the solution was brought to 15 ° C
= 7 for 2 hours. Thereafter, the methanol in the reaction solution is removed by evaporating under reduced pressure, followed by extraction with 40 g of toluene. The toluene extract is dried over anhydrous magnesium sulfate.

The toluene was removed by evaporation under reduced pressure.
13.6 g of iodoprop-1-yn-3-yl Nn-butyl carbamate was obtained. The melting point of the product is 65-67 ° C, the yield is 9
At 6.8 mol%, no impurities were detected by purity analysis.

Example 5 1-Iodoprop-1-yn-3-yl Nn-butylcarbamate was operated in the same manner as in Example 1 except that the reaction temperature was kept at 20 ° C. 13.6 g were obtained.
The melting point of the product was 65-67 ° C, the yield was 96.8 mol%, and no impurities were detected by the purity analysis.

Example 6 The procedure of Example 1 was repeated, except that 80 g of methanol was changed to 60 g of ethanol and 20 g of water.
13.8 g of 1-iodoprop-1-yn-3-yl Nn-butylcarbamate was obtained. The melting point of the product is 65-67 ° C, the yield is
At 98.3 mol%, no impurities were detected by the purity analysis.

Comparative Example 1 The procedure of Example 1 was repeated, except that 28% iodine monochloride (equivalent to 0.053 mol) was changed to 6.66 g (0.026 mol) of iodine. -Inn-3
-Yl N-n-butyl carbamate 7.3 g (yield 52.0
Mol%). According to the purity analysis, 1.2% of the periodic body (impurity) was detected.

Comparative Example 2 1-Iodoprop-1-yn-3-yl Nn-butylcarbamate was operated in exactly the same manner as in Example 1 except that the reaction temperature was kept at 50 ° C. 11.6g (Yield 8
2.3 mol%). According to the purity analysis, 1.5% of a periodic body (impurity) was detected.

Comparative Example 3 The procedure of Example 1 was repeated except that 28% iodine monochloride (equivalent to 0.053 mol) was changed to 13.20 g (0.52 mol) of iodine.
Operating exactly as in Example 1, 11.9 g of 1-iodoprop-1-yn-3-yl N-n-butylcarbamate (yield 8
4.7 mol%). According to the purity analysis, 2.5% of a periodic body (impurity) was detected.

Comparative Example 4 7.75 g of prop-1-yn-3-yl Nn-butylcarbamate was placed in a reactor (capacity: 200 ml, equipped with a condenser and a stirrer).
(0.050 mol) and 80 g of methanol, and 8.3 g (equivalent to 0.073 mol) of a 35% aqueous sodium hydroxide solution are added. 6.73 g iodine while cooling and maintaining the solution at 10 ° C
(Equivalent to 0.027 mol). Subsequently, 20.5 g of a 6% aqueous solution of sodium hypochlorite was added, and the mixture was reacted at a temperature of 10 ° C. for 2 hours. Thereafter, the reaction solution is neutralized with hydrochloric acid and extracted with 40 g of toluene.

Further, extraction is performed five times with toluene, and the toluene extract is dried over anhydrous magnesium sulfate. The toluene was removed by evaporation under reduced pressure to obtain 11.4 g of 1-iodoprop-1-yn-3-yl Nn-butylcarbamate.
The yield was 81.2 mol%. According to the purity analysis, 0.5% of the periodate (impurity) was detected.

[0046]

As described above, according to the present invention, the desired iodoalkynyl carbamate can be produced from the raw material alkynyl carbamate with high selectivity and high yield.

That is, when the iodine monochloride of the present invention is used as an iodinating agent, as shown in Examples 1 to 6, the yield of iodoalkynyl carbamate reaches as high as 96 to 99 mol%, Is not detected at all.
On the other hand, in Comparative Examples 1 to 4, which do not rely on the method of the present invention, the yield of iodoalkynyl carbamate was as low as about 52.0 to 84.7 mol%, and the purity was low and all were 0.5 to 2.5%.
It contains a periodic body. In particular, in Comparative Example 1 in which iodine was used as the iodination agent, the yield of iodoalkynyl carbamate was extremely low at 52 mol%, and the specific alkynyl carbamate was used as described above.
The effect of the present invention, which is characterized by iodination using iodine monochloride, is apparent.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Tanaka 1900 Togo, Mobara-shi, Chiba Mitsui Toatsu Chemicals Co., Ltd. (56) References JP-A-55-100354 (JP, A) Chem. Soc. , Chem. Commun. , (1985) No. 12 p. 817-p. 818 (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 269/06 C07C 271/12 C07C 271/34 CASREACT (STN)

Claims (1)

(57) [Claims] 1. The following general formula (1): ## STR1 ## [IC≡C— (CH ₂ ) _n —OCONH] _m R (1) wherein R has 1 to 20 carbon atoms. And an alkyl group,
An m-valent group derived from a cycloalkyl group, an aryl group or an aralkyl group, and may be further substituted with a halogeno group or a nitro group. M and n are integers of 1 to 3, respectively. A method for producing an iodoalkynyl carbamate represented by the following general formula (2): [HC≡C— (CH ₂ ) _n —OCONH] _m R (2) R, m, and n are the same as those described above), and an alkali metal hydroxide, an alkali metal carbonate, and an alkali metal in a mixed solvent of water and an alcohol in the solvent. One or more bases selected from the group consisting of bicarbonates,
And under conditions in which alkali metal chlorides are dissolved, 10
While maintaining the liquid temperature in the range of 40 ° C. to 40 ° C., iodine monochloride is allowed to act on the alkynyl carbamate of the general formula (2) to iodinate, thereby forming iodoalkynyl carbamate of the general formula (1). Converting the iodoalkynyl carbamate.