JPS6013784A - Thiophene derivative and herbicide - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R1 and R2 are H, lower alkyl or phenyl which may be substituted with Cl or CH3, provided that R1 and R2 are not H at the same time). EXAMPLE:1-Methyl-3-[1-methyl-1-(2-thienyl)ethyl-1-phenylurea. USE:A herbicide having excellent herbicidal activity against wide range of weeds, and exhibiting especially high controlling effect when applied to the surface of the soil or the leaf of the weed or in the water of the paddy field just before or after the sprouting of the weeds. PREPARATION:The compound of formula I can be produced by reacting the compound of formula II with a base such as pyridine in a solvent such as benzene, preferably at a temperature between the room temperature and the refluxing temperature of the solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thiophene derivative represented by the following general formula and a herbicide containing the compound as an active ingredient.

[In the formula, R1 and R2 are hydrogen, lower alkyl, phenyl (
may be substituted with C1, CH3). However, R,
=R2=excluding hydrogen. ] The thiophene derivative represented by the above general formula of the present invention is a new compound that has not been described in literature, patents, etc., and as a result of synthesizing it and carrying out various studies, it was recognized that it has excellent effects as a herbicide. .

That is, the compound of the present invention exhibits strong herbicidal activity against a wide range of weeds, and the active ingredient is applied at a dosage of 1 to 2 times per hectare immediately before the weeds germinate or at an early stage of their growth.
When applied at 0ky, it is possible to kill a wide range of weeds as described below within about 1 to 2 weeks.

In addition, by limiting the amount of this compound applied or by applying an appropriate application method, it can be used to treat specific crops such as corn, corn, yams, sugarcane, peanuts, soybeans, sunflowers, barley, wheat, turgid, paddy rice, cotton, and fruit trees. Weeds can be selectively removed in cultivation fields.

Examples of the compounds of the present invention that are similar to wheat substitutes include those shown in Table 1.

In addition, the compound is indicated by the symbol in the above general formula. Further, in the physical properties column, NMR indicates nuclear magnetic resonance spectrum, parentheses indicate solvent, mp indicates melting point, and η0 indicates refractive index, and the display method was according to a conventional method.

Table 1 The compounds of the present invention can be synthesized, for example, according to the following formula.

(R4 lol H, R2=H) (R4(H, R2) H) Suitable bases include tertiary amines such as pyridine and triethylamine, alkalis such as potassium carbonate and sodium carbonate, or sodium hydride. .

Solvent: tositehabenzene, toluene, chloroform, zochloromethane, zooxane, ethyl)I/X-thyl, tetrahydrofuran, acetone, methyl ethyl ketone, -) methylformamide 1. An inert solvent such as dimethyl sulfoxide, acetonitrile, or a tertiary solvent used as a base.
It is preferable to use a grade amine or the like.

The reaction temperature is generally from room temperature to the reflux temperature of the solvent.

Typical synthesis examples are shown below and explained in more detail.

Synthesis Example> Compound A2) 1.7 g of l-methyl-1-(2--1-enyl)ethyl isocyaner) in benzene solution KN-methylaniline 1. Add III and heat under reflux for 1.3 hours. After cooling, the mixture is washed with water, dried over magnesium sulfate, and the solvent is distilled off under reduced pressure to obtain crude compound A2. 7 of this crude product
When purified by 0-lysyl column chromatography (benzene solvent), the target compound A2 is converted to 2 as an oily substance.
．． 3g obtained.

2) Add 1.5 g of 1-methyl-1-(2-chenyl)ethylamine to a solution of 1.2 g of 1-(1-methyl-1-(2-chenyl)ephenyl isocyanate in cyclohexane 5 (17), Leave to stand overnight at room temperature. Separate the precipitated crystals and wash with water and then benzene. Recrystallize the obtained crude crystals from a mixed solvent of benzene/n-hexane to obtain the target compound AI. .2g obtained.

The active compounds according to the invention can be formulated into dosage forms such as emulsions, aqueous preparations, pastes, flowable powders, granules, etc. by applying conventional formulation methods.

Furthermore, the compounds of the present invention can be mixed with other herbicides. Furthermore, in order to expand the range of action, it can be used in combination with agricultural chemicals other than herbicides, such as insecticides and fungicides.

Next, examples of typical dosage forms will be given. "Department" in the description
indicates parts by weight Example 1 Wettable powder active ingredients: 50 parts of the compound shown in Table 1, 10 parts of diatom, 35 parts of clay, 73 parts of polyoxyethylene alkyl allyl ether sulfonic acid, and alkylnaphthalene sulfone. Two parts of acid soda are mixed and pulverized to obtain an aquarium containing 50 units of active ingredient compound.

When using, dilute with water to the specified humidity and spray.

Example 2 Granules 10 parts of the compound shown in Table 1, 20 parts of bentonite, 68 parts of clay
i and 2 parts of sodium dodecylbenzenesulfonate are mixed together, 20 parts of honsuri are added and kneaded in a mixer, then granulated through a granulator, and then dried and sized to produce granules containing 10% of the active ingredient. get the agent.

The novel thiophene rust conductor of general formula (2) has excellent herbicidal activity and is therefore suitable for controlling weeds growing in rice fields, fields, orchards, non-agricultural lands, etc.

When this active compound is applied to the soil surface or mixed into the soil, it is possible to completely inhibit the growth of weeds and kill them. Weeds can also be controlled by spraying a water solution on the stems and leaves of growing weeds.

The dosage of this compound is regulated and the application rate is 91% per hectare.
When the amount is selected to be 20 kg, it can be used as a selective herbicide in cultivated fields such as paddy rice, corn, wheat, barley, sugar cane, soybean, peanuts, sunflower, potato, cotton, or fruit trees. It can also be applied as a non-selective herbicide by increasing the application rate.

The compounds of the present invention can be used, for example, to control the following weeds: That is, dicotyledons, such as chickweed (Stellariamedia), Ch.
enopodium), Sagima j
aponica), Koa Turnip (Chonopodium)
ficlfolium), Japanese knotweed (Pol
ygonum nodosum), Spellhyu (Po
rtulaee oleracea), shepherd's purse (C
apsella bursapaa-toris), Lepidium virginicu
m), Porippa 1nd1ca
, Cardamelne hexuosa
), Ichibi (Abutilonavieennae)
), American golden deer (81da 5pinosa)
, Ipomoea purpurea
), yxo vulgari (5enecio vulgari)
s), Oninokeshi (5onchusasper)
, Bldeng frondo
sa), Arnbrosia artemi
siaefolla), Aster 5
ubulatus), Hotokenoza (Lamiumam)
plexicavle), oxalis (Oxalis
cornicolate), Amarant
hus retroflexus )) Crow pine pea (Vicia 5at1va), Yaemugura (Vicia 5at1va)
Galliumspurium), So.
lanum nigrum)% Datura IItramonium, Monochoria vaglnalis, etc.
Poaceae plants, such as Poaann 7 (Poaann)
ua ) Alopeculus a
equalis), Mehishino Z (Digitalia
Adsendens ), EleuIIl
neindiea), wild foxtail (5etaria)
virldlg), dogfish (Echinochl)
or crusgalli), Agro
pyron tsukushiensis )) lolium perenne (Lolium perenne), barley (Lolium perenne),
Bromuscatharticos), oat (Avena tatua), barnyard grass (Poly
pogon Hlgegaweri), Panicum dichotomifloram
), Cyperaceae weeds, such as Cyperus (c.
Cyperus microlria), Cyperus 1ria, Eleo
charig aclularia), etc. The compounds of the present invention have excellent herbicidal efficacy against a wide range of weeds such as those mentioned above, and are particularly effective against the weeds in the field blowing period or on the foliage surface of the plant body immediately before or after the weeds germinate. Extremely high pesticidal effects can be obtained when sprayed on trees or in flooded areas.

Also, when the compound of the present invention is mixed into soil, an extremely excellent weed control effect can be obtained.

In order to demonstrate the herbicidal effect of the herbicide according to the present invention, some representative test examples will be given and explained in more detail.

Test Example 1 Pre-emergence soil treatment (pre-emergence 5oi
herbicidal effect on plants when using
lls ), Golden millet (Eehinochloa cr
us-galli), Po-1ygo
num nodogum) % Amara
nthusretroflexus), corn (Zea mays), wheat (Triticum)
aetivum), Phaseolu
s radiatus), and covered with soil in approximately 5 seedlings, and immediately after that, the compounds listed in Table 1 were added to Example 1.
Prepare an irrigation agent according to the following, dilute it with water, and get the active ingredients per hectare! l) A dose corresponding to 10 kg was administered to the soil surface of each pot. Two weeks after treatment, the herbicidal effect on plants was fully investigated. The herbicidal effect was visually observed and expressed as a 6-level index from O: no effect to 5: complete withering.
Displayed in 2.

Test Example 2 Foliar 5play treat
ment) Herbicidal effect on plants when soiled Surface species: 100cm pot of volcanic ash soil ring topsnail, Digitarla sanguinalis
), Echinochloa krug-g
alli), Polygonum n.
odosum), Amaranthu+5
retroflexus), corn (zeam
ILy! +), wheat (Triticum ae+st
ivum), Yaenari (Phaseolus + ra)
dlatus) seeds are sown, covered with soil of approximately IG and placed in a greenhouse. When the weeds have one or two leaves, an irrigation agent of the compound of the present invention is applied at a dose of 1000 kg per hectare. It was diluted with water equivalent to A/ha and sprayed using a sprayer. Test Example 1 10 days after spraying the chemical
The survey was conducted using a similar base to the previous one, and the results were expressed using a 6-level index. The test results are as shown in Table 3.

Test Example 3 Herbicidal effect on paddy field weeds and phytotoxicity test on paddy rice A pot with a surface area of 120 cm2 was filled with paddy soil,
Monochoria vaginalig
seeds were mixed into the surface soil of approximately 2 countries, and
oaharls acicularis) and two-leaf stage rice weeds were transplanted to two locations each, and the water depth was approximately 31 yn.
Keep it. Three days later, an aquarium containing the compound of the present invention prepared according to Example 1 was administered into the water in an amount equivalent to plOkl+ per hectare.

Three weeks after chemical treatment, the herbicidal effect and chemical damage to paddy rice were investigated. The herbicidal effect and the chemical damage to crops were determined by Test Example 1.
The survey was conducted using the same criteria as the above, and was expressed using a 6-level index. The test results are as shown in Table 4.

It can be seen that the compounds of the present invention are effective in killing weeds such as Japanese grasshopper, Japanese grasshopper, and Japanese grasshopper, which are important weeds in rice fields.

Table 2 Pre-germination soil treatment Table 4 Flooding treatment

Claims (1)

[Claims] 1) General formula [In the formula, Rlr R2 represents hydrogen, lower alkyl, or phenyl (which may be substituted with CL or CH3). however,
R,=R2=excluding hydrogen. ] A thiophene derivative shown in 2) General formula [wherein R,, R2 are hydrogen, lower alkyl, phenyl (
may be substituted with C1, CH5). However, R,
=R2〒Hydrogen is excluded. ] A herbicide containing a thiophene derivative represented by as an active ingredient.