JPS6051180A - Preparation of 1,2,4-triazolin-5-one - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a herbicide economically, by chlorinating a specific compound obtained from hydrazine, etc. as starting raw materials. CONSTITUTION:A compound shown by the formula I (R is lower alkyl, alkoxyalkyl, or propargyl; R1 is lower alkyl, haloalkyl, or allyl; R2 is H, or lower alkyl) is reacted with a chlorinating agent such as thionyl chloride, sulfuryl chloride, etc. in an inert solvent such as acetonitrile, etc., to give a compound shown by the formula II. The compound shown by the formula I is obtained by reacting hydrazine shown by the formula III with a compound shown by the formula IV (R3 is lower alkyl) under heating to give a compound, reacting this compound with a compound shown by the formula R1Z (Z is halogen), reducing the reaction product, diazotizing it, decomposing it thermally to give a compound shwn by the formula V, reacting it further with a compound shown by the formula R.Z in an inert solvent.

Description

Detailed Description of the Invention The present invention relates to the general formula (I): (wherein R represents a lower alkyl group, an alkoxyalkyl group, an allyl group, a propalkyl group, and R1 represents a lower alkyl group, a haloalkyl group, an allyl group) and R2 represents a hydrogen atom or a lower alkyl group.

The compound produced by the method of the present invention is disclosed in JP-A-57-11
8079 and JP-A-57-J811]69, etc., and is a compound particularly useful as a herbicide.

The object of the present invention is to provide a new method for economically producing the above compound.

As a result of repeated research on the above-mentioned problem, the present inventors obtained the following formula 1.
1= (In the formula, R, R□ and R7 represent the same meanings as defined in Formula I.) By chlorinating the compound represented by the above formula ■
It has been found that 1,2,4-) riazolin-5-ones represented by the following formula can be obtained.

The production method of the present invention can be represented by the following formula: %Formula%(1) (wherein R, R, and R2 have the same meanings as above), and a compound represented by the general formula (It) is A compound represented by general formula (1) can be obtained by reacting a chlorinating agent in an inert solvent.

Examples of inert solvents that can be used in the present invention include, but are not limited to, acetonitrile, carbon tetrachloride, chlorhenzene, and acetic acid.
Any solvent may be used as long as it is inert to chlorination.

Examples of the chlorinating agent that can be used in the present invention include chlorine, thionyl sulfuryl chloride, phosphorus oxychloride, and phosphorus pentachloride.

The amount of the chlorinating agent to be used may be appropriately selected from the range of 1.0 to 50 mol, preferably 1.1 to 1.5 mol, per 1 mol of the compound represented by the general formula (It). It is.

The reaction temperature may be selected from the range of 0 to 150°C,
Further, the reaction time may be selected from the range of 0.5 to 6 hours.

After completion of the reaction, the desired product can be obtained by carrying out solvent extraction in a conventional manner, distilling off the solvent to obtain a crude product, and then purifying it by recrystallization or the like.

Table 1 below lists typical compounds represented by the general formula (+) obtained by the production method of the present invention, but the present invention is not limited thereto.

Table 1 The compound represented by the general formula (It) used as a raw material in the method of the present invention can be synthesized, for example, by the following steps.

(However, in the formula, R, R, and R9 have the same meanings as described above, R1+ represents a lower alkyl group, and Z represents a)-rogen atom. ) That is, by heating hydrazine represented by the formula (power) and a compound represented by the general formula (open) in an inert solvent, a ring-closing reaction is performed to form a compound represented by the general formula (to), and this compound ( ) in an inert solvent to the general formula (to)
This compound (Vl) is reduced in the presence of a reducing agent to form a compound represented by the general formula (■), and this compound (V) is is diazotized and then thermally decomposed to obtain a compound represented by the general formula (IV), and this compound is reacted with a compound represented by the general formula (ITl) in an inert solvent to form a compound represented by the general formula (n). A compound represented by can be obtained.

Examples of the present invention are shown below, but the present invention is not limited thereto.

Example 1 1-+7' lovargyloxyphenyl)-3-methyl-
4-difluoromethyl-Δ! -1.2.4-Triazolin-5-one 71F (0,025 mol) was dissolved in acetonitrile 75me and chlorine 4.3 f (0,0
6 mol) is introduced in 4 hours. After the reaction is completed, the reaction solution is poured into ice water, extracted with ethyl acetate, dried, and the solvent is distilled off to obtain crystals. By recrystallizing the obtained crystals from ethanol, 7.5 f of 1-(2,
4-dichloro-5-probargyloxyphenylene)
-3-Methyl-4-difluoromethyl-Δ2-1゜2.
4-) Riazolin-5-one is obtained.

Melting point 114.4°C Yield 860% Example 2 l-(3-isopropoxyphenyl)-3-methyl-4
-Difluoromethyl-Δ2-1.2.4-triazolin-5-one 7.1f (o, 02 s mol) was dissolved in 75 ml of acetonitrile, and under reflux, 7.4f of sulfuryl chloride
(0,055 mol) was added by 5 times and the reaction was carried out for 4 hours. After the reaction was completed, the reaction solution was poured into ice water and extracted with ethyl acetate.
After drying, the solvent is distilled off to obtain crystals. By recrystallizing the obtained crystals from n-hexane, 7
, 5 F of 1-(2,4-dichloro-5-inpropoxy)-6-methyl-4-difluoromethyl-Δ! '-1
,2,4-) riazolin-5-one can be obtained.

Melting point: 81.3°C Yield: 856% Example 3 1-(3-Pronoclyloxyphenyl) of Example 1
-3-Methyl-4-difluoromethyl-Δ2-1.2.
4-) Lyazo 1) Using 1-(3-isopropoxyphenyl)-3-methyl-4-difluoromethyl-Δ2-1.2°4-triazolin-5-one, A similar reaction was carried out with 89.2% yield of 1-
(2,4-dichloro-5-isopropoxyphenyl)-
3-Methyl-4-difluoromethyl-Δ2-1.2.4
-Triazolin-5-one was obtained.

Example 4 A similar reaction was carried out using chlorobenzene in place of acetonitrile in Example 1, and 1-(2,4-
Dichloro-5-)'ronochlorogyloxyphenyl)-5
-Methyl-4-difluoromethyl-ΔQ-1.2.4-
Triazo 1non-5-one was obtained.

Example 5 Sulfur chloride 1J Lua 4S' ((
8 & 5
1-(214-dichloro-5-)'ropargyloxyphenyl)-6-mesal-4-difluoromethyl-Δ2-1.2.4-toIJ azolin-5-one was obtained in a yield of 1.

(1 other person)

Claims (1)

[Claims] General formula (n): (In the formula, R represents a lower alkyl group, an alkoxyalkyl group, an allyl group, or a propargyl group, R1 represents a lower alkyl group, a haloalkyl group, or an allyl group, and R1 General formula (I) characterized by chlorinating a compound represented by (! indicates a hydrogen atom or a lower alkyl group): (However, in the formula, R, R1 and R2 are the same as defined in formula (■) A method for producing 1,2.4-) riazolin-5-ones represented by: