Tridiphane

Miscellaneous Other Herbicides. The herbicides in this group are not readily included in any of the preceding groups. Acrolein [107-02-8] (2-propenal) is used as a contact, aquatic herbicide. Sethoxydim, clethodim, and tridiphane are used for selective, post-emergence weed control. 

Ethanol and a number of other chemicals, including acetone and certain imidazoles, induce CYP2E1. Piperonyl butoxide, isosafrole, and other methylenedioxyphenyl compounds are known to induce CYP1A2 by a non-Ah receptor-dependent mechanism. Peroxisome proliferators, including the drug, clofibrate, and the herbicide synergist tridiphane induce a CYP4A isozyme that catalyzes the -oxidation of lauric acid. 

Nabu sethoxydim Nebijin flusulfamide Neguvon trichlorfen Nelpon tridiphane Nemacur fenamiphos Nemagon DBCP Nemathorin fosthiazate Neobyne barban Neocid DDT... 

Tachigaren hymexazol Tackle acifluorfen-sodium Tairel benalaxyl Takeoff imazosulfuron Taktic amitraz Talcord permethrin Talon brodifacoum Talstar bifenthrin Tamaron methamidophos Tamex butralin Tandem tridiphane Tandex karbutilate Taredan cadusafos Targa quizalofop-ethyl Task dichlorvos Techlead ipconazole Tecto thiabendazole Tedion tetradifon... 

Carbon disulfide captan, dazomet, dithianon, EXD, ferbam, folpet, hexythiazox, isoprothioiane, mancozeb, maneb, metam, methidathion, nabam, propineb, tebuthiuron, thicyofen, thiram, zineb, ziram Carbon monoxide fenuron Carbon oxy sulfide see carbonyl sulfide Carbon tetrabromide deltamethrin, tralomethrin Carbon tetrachloride cypermethrin, permethrin, tridiphane... 

Peracetic acid aldoxycarb, butoxycarboxim, dieldrin, dipyrithione, endrin, metconazole, tridiphane... 

Tridiphane, 2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane, is the active ingredient in Dow s new herbicide, TANDEM, which is being developed for postemergent weed control in corn. The material is the outgrowth of many years of research in The Dow Chemical Company in the... 

Since the meta-substituted epoxides were the most active herbicides, we next chose to look at the 3,5-disubstituted compounds. The first compound prepared was the 3,5-dichloro derivative, tridiphane, Its precursor, a-(2,2,2-trichloroethy 1)-3,5-dichlorostyrene, showed very little preemergent... 

With the discovery that the 3,5-dichloro analog was very active (10), a variety of 3,5-disubstituted compounds were prepared and tested. The 3,5-dimethyl epoxide 10 exhibited good activity in the greenhouse but under field conditions did not give season-long weed control while the 3-chloro-5-fluoro derivative 11 was somewhat more active than tridiphane. 

The major route of detoxification of tridiphane in corn has also been shown ... 

We have synthesized the glutathione conjugate of tridiphane and shown it to be inactive as a herbicide however, G. L. Lamoureux and D. G. Rusness (14,15) have found it to be an effective inhibitor of atrazine glutathione conjugation in vitro. 

Tridiphane is a unique molecule in many ways. It is certainly not a typical epoxide in its chemical reactivity. As shown in SCHEME V, it can be heated in glacial acetic acid at 100°C for eight hours with little or no change. 

One can open the epoxide, however, by treating it with sodium acetate in acetic acid at 85 °C for 48 hours and obtain the gylcol acetate, 12, in quantitative yield. Treatment of tridiphane with one equivalent of sodium methoxide in methanol at room temperature causes hydrogen chloride elimination and formation of the vinyl epoxide, 13, which has little herbicidal activity. In contrast to sodium methoxide, sodium methylthiolate readily opens the epoxide ring giving the / -thioalcohol, 14 in quantitative yield. 

Many pyridine compounds as well as primidines were synthesized and screened. The most active material is the direct pyridine analog, 17, which possessed activity equivalent to tridiphane. (16). 

In summary, with the discovery in Dow that a-(2,2,2-trichloroethyl) styrene possessed unique preemergent herbicidal activity and the synthesis and evaluation of close to one thousand related materials, a new product, tridiphane, the active ingredient in TANDEM will enter the marketplace in 1986. Tridiphane will be the first postemergent grass herbicide for use in corn and will be used in combination with triazine herbicides such as atrazine and cyanazine. 

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