Pyridaphenthion 哒嗪硫磷

哒嗪硫磷

英文通用名称 pyridaphenthion O，O-二乙基-O[2，3-二氢-3-氧代-2-苯基-6-哒嗪基]硫代磷酸酯
其他名称 哒净松、苯哒磷、哒净硫磷、苯哒嗪硫磷

制法
1.重氮化 将苯胺用亚硝酸钠，盐酸重氮化，配比为1：1.01：2.3（mol），亚硝酸钠配成35%~40水溶液，滴加温度为5°C以下，制成重氮盐
2.还原 重氮盐与过量亚硫酸钠反应，还原成苯肼。配比为1.0：2.2（以苯胺计）盐酸中和前反应液温度控制在70°C，时间30min，加盐酸调PH到6~7，升温回流0.5H
3.缩合 顺丁烯二酸酐与苯肼（常用其盐酸水溶液）反应制得哒嗪酮。苯肼与酸酐配比为1：1（按苯胺计），反应温度100~109°C，时间4h，负压操作
4.哒嗪硫磷的合成 在水相中以液碱和纯碱为脱酸剂，以三甲胺为催化剂，反应温度65~70°C，O,O-二乙基硫代磷酰氯与哒嗪酮、碱液配比为1：1.1：0.9，终点控制PH8

毒性
哒嗪硫磷属低毒低残留广谱性硫逐式一硫代磷酸酯类杀虫杀螨剂，用大量试验未见对皮肤有刺激症状，未见致癌、致畸、致突变现象， 对鱼、鸡有毒。 剂型 20%哒嗪硫磷乳油，2%哒嗪硫磷粉剂。

性能
高效、低毒、低残留广谱性的有机磷杀虫剂,纯品为白色结晶，熔点54.5-56℃。对热、光照、酸性介质稳定，强碱介质中不稳定。难溶于水，可溶于一般有机溶剂。对高等动物毒性较低，对鱼类相对无毒。对害虫害螨具有触杀和胃毒作用，但无内吸作用,且有一定杀卵作用。具有低毒、低残留、不易诱发害虫抗药性等特点。

适用范围
哒嗪硫磷对多种咀嚼式口器和刺吸式口器害虫均有较好效果。使用方法为乳油对水喷雾或粉剂喷粉。此药剂对水稻害虫药效突出，对水稻害虫的天敌捕食螨较安全，对鱼类低毒，在稻谷中残留量低，特别适合用于水稻，可防治螟虫、纵卷叶螟、稻苞虫、飞虱、叶蝉、蓟马、稻瘿蚊等。对棉叶螨特效，对成蟥、若螨、螨卵都有显著抑制作用，还可防治棉蚜、棉铃虫、红铃虫。用于小麦、杂粮、油料、蔬菜、果树等作物及林木，可防治多种咀嚼式口器、刺吸式口器害虫及叶螨。注意不可与2，4-滴类除草剂同时或近时使用，以免造成药害。

使用方法
1．水稻害虫的防治 二化螟、三化螟每亩用20%乳油200--300毫升，对水10千克喷雾。 稻苞虫、稻叶蝉、稻蓟马每亩用20%乳油200毫升，对水100千克喷雾。 稻飞虱、稻纵卷叶螟也可用此剂量进行防治。 稻瘿蚊每亩用20%乳油200--250毫升，对水75千克喷雾，或混细土1.5-2.5千克撒施。
2．棉花害虫的防治 棉花叶螨用20%乳油稀释1000倍液喷雾。棉蚜、棉铃虫、红铃虫、造桥虫用20%乳油500-1000倍喷雾。或每亩用2%粉剂3千克喷粉，效果良好。

注意事项
1． 不能与2，4-滴除草剂混合使用，不能与碱性农药混用。
2． 哒嗪硫磷中毒为典型的有机磷中毒症状，解救方法与其他有机磷相同。

pyridaphenthion
Insecticide, acaricide
IRAC 1B; organophosphate

NOMENCLATURE
Common name pyridaphenthion (JMAF)
IUPAC name O-(1,6-dihydro-6-oxo-1-phenylpyridazin-3-yl) O,O-diethyl phosphorothioate
Chemical Abstracts name O-(1,6-dihydro-6-oxo-1-phenyl-3-pyridazinyl) O,O-diethyl phosphorothioate
CAS RN [119-12-0] Development codes NC-250; CL 12503 (Cyanamid)

PHYSICAL CHEMISTRY
Mol. wt. 340.3 M.f. C14H17N2O4PS Form Pale yellow solid. M.p. 54.5-56.0 ºC V.p. 0.00147 mPa (20 ºC) KOW logP = 3.2 Henry 5.00 ´ 10-6 Pa m3 mol-1 (calc.) S.g./density 1.325 (20 ºC) Solubility In water 100 ppm (20 °C). In acetone 3.77, methanol 2.66 (both in kg/kg, 21 ºC); in diethyl ether 1.01 kg/kg (25 ºC).

COMMERCIALISATION
History Insecticide introduced in Japan (1974) by Mitsui Toatsu Chemicals, Inc. (now Mitsui Chemicals, Inc.). Manufacturers Mitsui

APPLICATIONS
Biochemistry Cholinesterase inhibitor. Mode of action Insecticide and acaricide with contact and stomach action. Uses Control of sucking and chewing insects (e.g. stem borers, leaf rollers, leafhoppers, planthoppers, leaf beetles, skippers, grasshoppers, thrips, aphids, sawflies, lace bugs, caterpillars, onion flies, bean seed flies, etc.) and spider mites on paddy rice, vegetables, fruit, and ornamentals. Also effective against Isoptera in public health. Formulation types DP; EC; UL; WP. Compatibility Incompatible with alkaline products. Selected products: 'Ofunack' (Mitsui); 'Oreste' (Sipcam Phyteurop)

ANALYSIS
Product and residue analysis by glc.

MAMMALIAN TOXICOLOGY
Oral Acute oral LD50 for male rats 769, female rats 850, mice 459, dogs >12 000 mg/kg. Skin and eye Acute percutaneous LD50 for male rats 2300, female rats 2100 mg/kg. Non-irritating to skin (rabbits). Inhalation LC50 (4 h) for rats >1133.3 mg/m3. Other In teratogenicity, mutagenicity, carcinogenicity, and multigeneration chronic toxicity studies on rats, no adverse effects were observed. Toxicity class WHO (a.i.) III

ECOTOXICOLOGY
Birds Acute oral LD50 for Japanese quail 68 mg/kg. Fish TLm (48 h) for carp 12 ppm. Daphnia TLm (3 h) 0.02 mg/l. Bees LD50 0.08 mg/bee.

ENVIRONMENTAL FATE
EHC 63 (WHO, 1986; a general review of organophosphorus insecticides). Animals In mice and rats, the parent compound, O-ethyl-O-(3-oxo-2-phenyl-2H-pyridazine-6-yl) phosphorothioate and the corresponding phosphate are found. Plants In rice, phenyl maleic hydrazide (PMH), O,O-diethyl thiophosphoric acid, and PMH glycoside are formed. Soil/Environment Soil DT50 11-24 d.