Trifloxysulfuron 三氟啶磺隆

棉田用除草剂。2011年3月24日到期。先正达公司开发。2009年市场0.60亿美元。2001年上市。

三氟啶磺隆

三氟啶磺隆是一种除草剂，主要用于防除棉花田和甘蔗田中的阔叶杂草和香附子等莎草科杂草。
英文名称：Trifloxysulfuron。
化学名称：1-(4,6-二甲氧基嘧啶-2-基)-3-[3-(2,2,2-三氟乙氧基)-2-吡啶磺酰脲。
分子式：C14H14F3N5O6S 。
分子量：437.35。
CAS编号：145099-21-4。

理化性质
本品外观为白色结晶。比重(20℃，纯品)1.63g/cm3，熔点：195℃。纯品在熔化后立即开始热分解，蒸气压：(25℃，纯品)<1.3×10-6Pa，溶解度(25℃)水中25.7g/L、丙酮17g/L、甲醇50g/L、甲苯>500g/L、正己烷<1mg/L、辛醇4.4g/L。

常用剂型
10%三氟啶磺隆可湿性粉剂、75%三氟啶磺隆水分散粒剂。

适用作物
棉花、甘蔗。

防除对象
主要用于防除阔叶杂草和莎草科杂草。对苣荬菜（苦苣菜）、藜（灰菜）、小藜、灰绿藜、马齿苋、反枝苋、凹头苋、绿穗苋、刺儿菜、刺苞果、豚草、鬼针草、大龙爪、水花生、野油菜、田旋花、打碗花、苍耳、醴肠（旱莲草）、田菁、胜红蓟、羽芒菊、臂形草、大戟、醡浆草（酸咪咪）等阔叶杂草具有很好的防除效果；对香附子（三棱草）有特效；对马唐、旱稗、牛筋草、狗尾草、假高粱等禾本科杂草防效较差。

作用机理
三氟啶磺隆是属于磺酰脲类除草剂，施药后可被杂草的根、茎、叶吸收，可在植物体内向下和向上传导，通过抑制乙酰乳酸合成酶（ALS）的活性，从而影响支链氨基酸（如：亮氨酸、异亮氨酸、缬氨酸等）的生物合成。植物受害后表现为生长点坏死、叶脉失绿，植物生长受到严重抑制、矮化，最终全株枯死。
三氟啶磺隆对杂草和作物的选择性主要是由于降解代谢的差异。其在棉花和甘蔗体内可以被迅速代谢为无活性物质，从而使作物植株免受伤害。

使用方法
棉花5叶以后或株高20厘米以上时，一般用量为75%三氟啶磺隆水分散粒剂本品1.5-2.5克/亩，或10%三氟啶磺隆可湿性粉剂15-20克/亩，兑水20-30千克，均匀喷雾杂草茎叶，喷药时尽量避开棉花心叶（主茎生长点）。
甘蔗生长期，杂草3-6叶期，一般用量为75%三氟啶磺隆水分散粒剂本品1.5-2.5克/亩，或10%三氟啶磺隆可湿性粉剂15-20克/亩，兑水20-30千克，均匀喷雾杂草茎叶，甘蔗对本品具有较强的耐药性，以推荐剂量的2倍施用于甘蔗田，仍未出现药害。

注意事项
1．每季作物只能使用本品1次。
2．本品主要用于甘蔗和棉花除草，如果用于其它作物，请先进行安全性试验。
3．本品在棉花田喷药时，应尽量避开棉花心叶。
4．本品对个别品种的棉花叶片有轻微灼伤，1周后可以迅速恢复，不影响产量。

trifloxysulfuron-sodium
Herbicide
HRAC B WSSA 2; sulfonylurea

NOMENCLATURE
trifloxysulfuron-sodium
CAS RN [199119-58-9] Development codes CGA 362622 (Ciba-Geigy)

trifloxysulfuron
Common name trifloxysulfuron (BSI, pa ISO)
IUPAC name 1-(4,6-dimethoxypyrimidin-2-yl)-3-[3-(2,2,2-trifluoroethoxy)-2-pyridylsulfonyl]urea
Chemical Abstracts name N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-3-(2,2,2-trifluoroethoxy)-2-pyridinesulfonamide
CAS RN [145099-21-4] Development codes CGA 292230 (Ciba-Geigy)

PHYSICAL CHEMISTRY
trifloxysulfuron-sodium
Mol. wt. 459.3 M.f. C14H13F3N5NaO6S Form Odourless, white to off-white powder. M.p. 170.2-177.7 °C V.p. <1 ´ 10-3 mPa (25 °C) KOW logP = 1.4 (pH 5), -0.43 (pH 7) (25 °C) Henry 2.6 ´ 10-5 Pa m3 mol-1 (calc.) S.g./density 1.63 g/cm3 (21 °C) Solubility In water 25 700 mg/l (pH 7.4, 25 °C). Stability Hydrolysis DT50 6 (pH 5), 20 (pH 7), 21 (pH 9) (all in d, 25 °C); photolysis DT50 7 h (25 °C). pKa 4.76 (20 °C)

trifloxysulfuron
Mol. wt. 437.4 M.f. C14H14F3N5O6S

COMMERCIALISATION
History Reported by Hudetz et al., Proc. South. Weed Sci. Soc. 53, 163-166 (2000) and by S Howard et al., (Proc. BCPC Conf. - Weeds, 2001, 1, 29). Discovered in 1995 and under development by Syngenta AG; Patents EP-B-540697; US-A-5403814 Manufacturers Syngenta

APPLICATIONS
Biochemistry Inhibitor of acetolactate synthase. Cotton tolerance is based on enhanced metabolism and low translocation out of the treated leaves. Mode of action Readily absorbed by shoots and roots and is translocated via xylem and phloem to shoots, roots and apical meristems. Susceptible weeds show chlorotic symptoms within days and die within 1-3 weeks. Uses The sodium salt is under development for post-emergence grass, sedge, and broad-leaved weed control, at 5-7.5 g/ha, in cotton, and, at 1500 g/ha, in admixture with ametryn, in sugar cane. Weed control in plantations and in turf are also being examined. Weeds controlled include Cyperus spp., Euphorbia spp., Ipomoea spp., Cassia spp., Xanthium spp., Brachiaria spp., and Rottboellia exaltata. Formulation types WG. Selected products: 'Envoke' (Syngenta); mixtures: 'Krismat' (+ ametryn) (Syngenta)

OTHER PRODUCTS
trifloxysulfuron-sodium
'Enfield' (Syngenta)

ANALYSIS
By HPLC; for details, contact Syngenta AG.

MAMMALIAN TOXICOLOGY
Oral Acute oral LD50 for rats >5000 mg/kg. Skin and eye Acute percutaneous LD50 for rats >2000 mg/kg. Non-irritating to skin and eyes (rabbits). Not a skin sensitiser (guinea pigs). Inhalation LC50 for rats (4 h) >5.03 mg/l. NOEL NOAEL (2 y) for rats 500 ppm. ADI 0.15 mg/kg b.w. Other Not mutagenic, not genotoxic, not teratogenic, not a reproductive hazard; not a neurotoxin. Toxicity class WHO (a.i.) III (company classification)

ECOTOXICOLOGY
trifloxysulfuron-sodium
Not harmful to most organisms but highly toxic to green algae and certain aquatic plant species. Birds LD50 for mallard ducks >2000, bobwhite quail >2250 mg/kg. Dietary NOEC for mallard ducks and bobwhite quail 5620 ppm. Fish LC50 (96 h) for rainbow trout and bluegill sunfish >103 mg/l. Daphnia EC50 (48 h) >108 mg/l. Algae IC50 (120 h) for Navicula >150, Skeletonema 80, Anabaena 0.28, Selenastrum 0.0065 mg/l. Other aquatic spp. EC50 (96 h) for Eastern oyster >103 mg/l, mysid shrimp 60 mg/l. Bees LD50 (48 h) (oral and contact) >25 mg/bee. Worms Acute LC50 (14 d) >1000 mg/kg soil. Other beneficial spp. Not harmful to Typhlodromus, Aphidius, Poecilus; no effect on soil microbes (respiration, nitrification) or on activated sewage sludge.

ENVIRONMENTAL FATE
Rapidly absorbed and degraded, and shows no tendency to accumulate in organisms or the environment. Animals Rapidly absorbed and excreted (c. 70% via urine, 6% via faeces); after 7 d, remaining residues were <0.3% of dose; metabolism is via O-demethylation, bridge cleavage, glucuronide conjugation. Plants Metabolism proceeds via Smile's rearrangement, bridge cleavage, various hydrolytic, oxidative, and conjugation reactions; very low residues in edible parts of target crops (cane stalk, cotton seed). Soil/Environment Soil adsorption Koc 29-584 ml/cm3 depending on soil type and pH; increasing adsorption over time; Degrades in soil mainly by hydrolysis. DT50 (20 °C, 40% MWC; various soils) 49-78 d. Aqueous DT50 (aerobic) 7-25 d.