Cinmethylin 环庚草醚

环庚草醚

CAS登录号：87818-31-3
英文名称：cinmethylin
化学名称：1-甲基-4-(1-甲基乙基)-2-(2-甲基苯基甲氧基)-7-噁二环[2,2,1]庚烷；(1RS,2RS,4RS)-1,4-epoxy-p-menth-2-yl-2-metnyl-benzyl ether;
其他名称：艾割，仙治，恶庚草烷，Argold， Cinch
分子式：C18H26O2
分子量：274.4

理化性质：纯品为深琥珀色液体。密度1.014(20℃)，沸点313℃，蒸气压10mPa(20℃)，20℃时水中溶解度63mg/L，溶于任何比例下的大多数有机溶剂。

小于等于145℃稳定，25℃、pH3～11水解30d(DT50)，模拟日光照射100h后，从有机溶剂或水中回收70%～100%，但在石英上的薄片则完全分解。

毒性LD50(mg/kg)：　　大鼠急性经口3960，大属急性经皮>2000，对兔眼睛和皮肤有轻微刺激作用。两年饲喂试验的无作用剂量：大鼠300mg/kg，小鼠30mg/kg。鹌鹑急性经口大于2150mg/kg，野鸭急性经口>5620mg/kg。鱼毒LC50(96h,mg/kg)：虹鳟鱼6.6，蓝鳃鱼6.4。水虱LC50(48h)7.2mg/L。

作用特点及杀草谱：　　本品属桉树脑（cineole）类除草剂。抑制分生组织生长。水稻移植后，本品以25～100g（a.i.）/ha施用，可有效防除大多数禾本科杂草，如稗、鸭舌草、异型莎草等。以≥200g（a．i.）/ha（下同）施用时，对稗草防效优异，施药期较宽，从稗草芽前期至3叶期施药均可。在我国以15～25g/ha施用，对稗草防效优异，鸭舌草、节节菜和一年生莎草科杂草对本品也敏感，在插秧后施药（施药量200g/ha）对移栽水稻安全。在菲律宾，水稻移栽后4～10d，以100g/ha施药，可防除稻田主要杂草，如稗草、异型莎草等。在日本，以90～100g/ha施药。可有效防除一年生和多年生杂草。对稗草以芽前至2．5叶期施药防除效果较好。

剂型：10%乳油，10%环庚草醚•苄可湿性粉剂（江苏克胜省力宝）；22%环庚•三环可湿性粉剂，８．８％环庚草醚•苄可湿性粉剂（杭州天一灭草星 ）

生产方法：　三甲基乙酸、（土）-萜烯-4-醇、双（2，4-戊二酸）钒（Ⅳ）氧化物在二气甲烷中加热回流2h，然后滴加对甲基苯磺酸，反应混合物回流，得到（土）-2-挂－羟基－1-甲基－4-异丙基－7-氧杂双环[2，2，2，］庚烷，再与邻甲基氯苄在氢氧化钠存在下反应，即制得环庚草醚。

生产情况：　德国拜耳；江苏山达化工有限公司；江苏省宜兴市益农化工厂

cinmethylin
Herbicide
HRAC Z

NOMENCLATURE
Common name cinmethylin (BSI, draft E-ISO, ANSI, WSSA); cinméthyline ((f) draft F-ISO)
IUPAC name (1RS,2SR,4SR)-1,4-epoxy-p-menth-2-yl 2-methylbenzyl ether
Chemical Abstracts name exo-(?-1-methyl-4-(1-methylethyl)-2-[(2-methylphenyl)methoxy]-7-oxabicyclo[2.2.1]heptane
CAS RN [87818-31-3] exo-(?- isomers; [87818-61-9] exo-(+)- isomer; [87819-60-1] exo-(-)- isomer Development codes SD 95 481 (Shell); WL 95 481 (Shell)

PHYSICAL CHEMISTRY
Mol. wt. 274.4 M.f. C18H26O2 Form Dark amber liquid. B.p. 313 ºC/760 mmHg V.p. 10.1 mPa (20 ºC) KOW logP = 3.84 Henry 4.40 ´ 10-2 Pa m3 mol-1 (calc.) S.g./density 1.014 g/ml (20 ºC) Solubility In water 63 mg/l (20 ºC). Miscible with a range of organic solvents. Stability Thermally stable up to 145 ºC. Hydrolytically stable from pH 5 to pH 9 at 25 ºC. Light-catalysed decomposition occurs in the presence of air. F.p. 147 °C (ASTM D93)

COMMERCIALISATION
History Herbicide reported by J. W. Way et al. (Proc. 1985 Br. Crop Prot. Conf. - Weeds, 1, 265). Introduced by Shell International Chemical Co. Ltd (now BASF AG) in China (1989) and by E. I. du Pont de Nemours Co. (who no longer manufacture or market it). Manufacturers BASF

APPLICATIONS
Biochemistry May be metabolically activated, by cleavage of the benzyl ether, to form an analogue of naturally-occurring 1,4-cineole, which then inhibits asparagine synthetase (F. E. Dayan et al., Abstr. III Int. Weed Sci. Congr., Brazil, June 2000). Mode of action Absorbed from paddy water through the shoots and roots of germinating or emerging weeds. Moves upwards through the plant and disrupts meristematic development in growing points of roots and shoots. Uses Control of important weeds of rice, including Echinochloa spp., Monochoria vaginalis, and Cyperus difformis, by post-transplanting application, at 20-100 g/ha. Formulation types EC; GR. Compatibility Can be tank-mixed with broad-leaved weed herbicides. Selected products: 'Argold' (BASF)

OTHER PRODUCTS
Discontinued products: 'Cinch' * (DuPont)

ANALYSIS
Product and residue analysis by glc. Details available from BASF.

MAMMALIAN TOXICOLOGY
Oral Acute oral LD50 for rats 3960 mg/kg. Skin and eye Acute percutaneous LD50 for rats and rabbits >2000 mg/kg; moderate skin and mild eye irritant to rabbits. Inhalation LC50 (4 h) for rats >3.5 mg/l. NOEL (2 y) for rats 100, mice 30 mg/kg diet. Toxicity class WHO (a.i.) U; EPA (formulation) III EC classification Xn; R20| N; R51, R53

ECOTOXICOLOGY
Birds Acute oral LD50 for bobwhite quail >2150 mg/kg. Dietary LC50 (5 d) for bobwhite quail and mallard ducks >5620 mg/kg diet. Fish LC50 (96 h) for rainbow trout 6.6, bluegill sunfish 6.4, sheepshead minnow 1.6 mg/l. Daphnia LC50 (48 h) 7.2 mg/l. Other aquatic spp. LC50 for fiddler crab >1000 mg/l.

ENVIRONMENTAL FATE
Animals For a study of the metabolism of cinmethylin in the goat, see J. Agric. Food Chem., 1989, 37, 787. Soil/Environment Strongly adsorbed by soils (B. T. Grayson et al., Pestic. Sci., 1987, 21, 143), but relatively short-lived in the environment, being broken down in the soil under aerobic conditions with DT50 23-75 d, depending on soil texture. Under anaerobic conditions (as may be found in paddy rice), the rate of metabolism is reduced because of slower microbial breakdown.