Difenzoquat 野燕枯

野燕枯

CAS 登录号：49866-87-7

英文名：Difenzoquat

化学名称：1,2-二甲基-3,5-二苯基吡唑；1,2-Dimethyl-3,5-diphenyl-1H-pyrazolium

其他名称： 草吡唑;燕麦枯;双苯唑快;

分子式：C17H17N2

分子量：249.33

结构式：

理化性质：无色吸湿性晶体，密度：1.13（20℃），熔点150－160℃(原药)，蒸气压：13.33μPa(20℃)，溶解度水 765g/L(25℃)，780（37℃），850（56℃）。二氯甲烷 360、氯仿500、甲醇588、1,2－二氯乙烷71、异丙 醇23、丙酮9.8、二甲苯、己烷<0.01(g/L，25℃)，微溶于石油醚、二恶烷，水 溶液中对光稳定，热稳定，弱酸性介质中稳定，强酸分解并氧化。土具强吸附，半衰期约3月

毒性：急性经口LD50：470mg/kg，急性经皮LD50：3540mg/kg(兔)，水生生物：Ld50(96小时),兰鳃鱼696mg/kg，虹鳟鱼694mg/L。蜜蜂：LD50(接触)0.036mg/蜂。天敌：LC50(8天膳食mg/kg)北美鹌鹑>4640,野鸭>10388

作用特点及用途：选择性苗后茎叶处理除草剂。主要用于小麦、大麦、黑麦田防除野燕麦，防除效果达到90%左右，也用于油菜、亚麻等作物田。作用于燕麦植株的生长点，使顶端、 节间分生组织中细胞分裂和伸长受破坏，抑制植株生长。用药量:每公顷用64%野燕枯1875-2340克。使用时期:在3叶至分蘖期施药。可与2，4滴丁酯、2甲2氯等混用。

注意事项：1．相对湿度65％以下、气温15℃以下不要施药。 2．施药后应保持4小时无雨。 3．野燕枯不能与钠盐、胺盐混用，以免产生沉淀，影响药效。 4．40％燕麦枯水剂在北方冬季应放温室贮存，遇零度以下低温会结晶，难以再溶解而失去使用价值。（摘自王险峰主编《除草剂作用手册》）

剂型：64％野燕枯可湿性粉剂、40％野麦枯水剂

生产方法：按下述步骤合成：（1）由苯乙酮、苯甲醛、双氧水合成2,3-环氧-1,3-二苯基丙酮-1（称环氧化物）。（2）由2,3-环氧-1,3-二苯基丙酮-1与水合肼合成3,5-二苯基吡唑。（3）3,5-二苯基吡唑与硫酸二甲酯反应得草吡唑。原料消耗定额：苯乙酮（工业品）660kg/t、苯甲醛（95%）590kg/t、氢氧化钠（95%）190kg/t、乙醇（95%）140kg/t、水合肼（85%）290kg/t、二甲苯270kg/t、双氧水（30%）770kg/t、对甲苯磺酸（工业品）20kg/t、硫酸二甲酯（95%）710kg/t、二甲基甲酰胺350kg/t。

生产情况：野燕枯是美国氰胺公司研究开发的除草剂,于1974年注册投产。目前国内登记用于大麦田的野燕枯产品只有德国巴斯夫股份有限公司；国内有陕西农大德力邦科技股份有限公司（陕西省武功化工厂）

difenzoquat metilsulfate
Herbicide, fungicide
HRAC Z WSSA 8

NOMENCLATURE
difenzoquat metilsulfate
Common name difenzoquat metilsulfate
IUPAC name 1,2-dimethyl-3,5-diphenyl-1H-pyrazolium methyl sulfate
Chemical Abstracts name 1,2-dimethyl-3,5-diphenylpyrazolium methyl sulfate
Other names difenzoquat methyl sulfate CAS RN [43222-48-6] EEC no. 256-152-5 Development codes AC 84 777 ; CL 84 777 (both Cyanamid); BAS 450H (BASF)

difenzoquat
Common name difenzoquat (BSI, E-ISO, (m) F-ISO, ANSI, WSSA)
IUPAC name 1,2-dimethyl-3,5-diphenylpyrazolium
Chemical Abstracts name 1,2-dimethyl-3,5-diphenyl-1H-pyrazolium
CAS RN [49866-87-7]

PHYSICAL CHEMISTRY
difenzoquat metilsulfate
Composition Tech. grade is ³96% pure. Mol. wt. 360.4 M.f. C18H20N2O4S Form Colourless, hygroscopic crystals. M.p. 156.5-158 °C V.p. <1 ´ 10-2 mPa (25 °C) KOW logP = 0.648 (pH 5), -0.62 (pH 7), -0.32 (pH 9) Henry <5.7 ´ 10-11 Pa m3 mol-1 S.g./density 0.8 (25 °C) Solubility In water 817 g/l (25 ºC). In dichloromethane 360, chloroform 500, methanol 558, 1,2-dichloroethane 71, isopropanol 23, acetone 9.8, xylene, heptane <0.01 (all in g/l, 25 ºC). Slightly soluble in petroleum ether, benzene, and dioxane. Stability Stable to light in aqueous media; t1/2 28 d. Thermally stable. Stable in weakly acidic media, but decomposed by strong acids and oxidants. pKa c. 7 F.p. >82 °C (Tag open cup)

difenzoquat
Mol. wt. 249.3 M.f. C17H17N2

COMMERCIALISATION
History Herbicidal properties of difenzoquat metilsulfate (the methyl sulfate) reported by T. R. O'Hare & C. B. Wingfield (Proc. North Cent. Weed Control Conf., 1973). This salt introduced by American Cyanamid Co. (now BASF AG); US registration in 1982. Patents BE 792801; US 3882142 Manufacturers BASF

APPLICATIONS
difenzoquat metilsulfate
Mode of action Selective herbicide, absorbed by the leaves, with translocation mainly acropetally, and accumulation mostly near the treated area. Meristem inhibitor. Uses Post-emergence control of wild oats in barley, wheat, rye, maize, ryegrass, and flax; applied at 750-1100 g/ha when used alone. Also used as a fungicide to control powdery mildew in cereals. Formulation types SL; SP. Compatibility Compatible with many broad-leaved herbicides, cereal fungicides, and the growth regulator chlormequat chloride. Selected products: 'Avenge' (herbicide) (BASF); 'Match' (fungicide) (BASF)

OTHER PRODUCTS
difenzoquat metilsulfate
'Yeh-Yan-Ku' (BASF) Discontinued products: 'Avenge 2' * (Cyanamid); 'Finaven' * (Cyanamid)

ANALYSIS
Product analysis by colorimetry (W. A. Steller, Anal. Methods Pestic. Plant Growth Regul., 1980, 11, 291). Residues determined by glc (W. A. Steller, loc. cit.).

MAMMALIAN TOXICOLOGY
difenzoquat metilsulfate
Reviews "Report of the Food Quality Protection Act (FQPA) Tolerance Reassessment Progress and Risk Management Decision (TRED) for difenzoquat" US EPA, 19th April 2002. Oral Acute oral LD50 for male rats 617, female rats 373, male mice 31, female mice 44 mg/kg. Skin and eye Acute percutaneous LD50 for male rabbits 3540 mg/kg. Moderate skin and severe eye irritant (rabbits). Inhalation LC50 (4 h) for female rats 0.36, male rats 0.62 mg/l. NOEL In 2 y feeding trials, rats receiving 500 mg/kg diet showed no ill-effects. NOAEL 25 mg/kg daily. ADI 0.2 mg/kg b.w. Toxicity class WHO (a.i.) II; EPA (formulation) I (tech.) EC classification Xn; R22| N; R50, R53: (T; R22, R23, R41| N; R50, R53)

ECOTOXICOLOGY
difenzoquat metilsulfate
Birds Dietary LC50 (8 d) for bobwhite quail >4640, mallard ducks >10 388 mg/kg diet. Fish LC50 (96 h) for bluegill sunfish 696, rainbow trout 694 mg/l. Daphnia LC50 (48 h) 2.63 mg/l. Algae Very toxic. Bees Contact LD50 36 mg/bee.

ENVIRONMENTAL FATE
Animals In rats, following oral administration, difenzoquat metilsulfate is excreted unchanged in the urine and faeces. Plants No significant metabolism of difenzoquat metilsulfate occurs in plants, removal being by photolytic demethylation to the monomethyl pyrazole. Soil/Environment Strongly adsorbed by soil; Kd c. 400, Koc c. 30 000. No significant microbial degradation occurs. Half-life in soil is c. 3 months.