申请人:Siegfried Aktiengesellschaft
公开号:US04443612A1
公开(公告)日:1984-04-17
1-Aryl-2-(1H-imidazol-1-yl)-ethanone oxime ethers are known to exist as a mixture of isomers corresponding to the formulae: ##STR1## To prepare such an isomer in a stereospecifically pure form, the pure stereoisomer of the corresponding ethanone oxime is first converted into an alkali salt in a polar solvent, such as acetone or dimethylformamide, using an alkali in an amount somewhat less than the equimolar amount with respect to the said ethanone oxime, and is then converted to the desired ether by reacting it at a temperature not higher than 40.degree. C. with a halogen compound capable of forming the desired ether. Isolation of the ether product is obtained as the free base or by precipitating it as an acid addition salt upon addition of a suitable organic or mineral acid, preferably nitric acid. A stereospecific ethanone oxime in either its trans- or cis-isomer form corresponding to the formula: ##STR2## can be stereospecifically synthesized from the corresponding 2-halogen ethanone having the formula A--CO--CH.sub.2 --Hal (IV) which, in making the cis oxime (II.sub.c), is first converted with imidazole or a suitably substituted derivative thereof and subsequently oximated by reaction with hydroxylamine in the presence of a molar excess of an alkali at an elevated temperature; or which, in preparing the trans oxime (II.sub.t), is first oximated by reaction with hydroxyl-amine under mild conditions and subsequently converted in the cold with imidazole or a suitably substituted derivative thereof. The products are effective fungicides or bactericides and consequently useful as thermotherapeutic agents in combatting undesirable lower plant organisms in the fields of human as well as veterinary medicine and also as fungicides in agriculture and horticulture.
1-芳基-2-(1H-咪唑-1-基)-乙酮肟醚以混合异构体的形式存在,对应于以下式子:##STR1##
为了制备这样的立体特异性纯异构体,首先将对应的乙酮肟的纯立体异构体在极性溶剂(例如丙酮或二甲基甲酰胺)中用少于等摩尔量的碱转化为碱盐,然后通过与能够形成所需醚的卤素化合物在不高于40℃的温度下反应来将其转化为所需的醚。醚产物的分离可通过以自由碱基形式获得,或者通过添加适当的有机酸或矿物酸(最好是硝酸)沉淀为酸加合盐。可以从相应的2-卤代乙酮(式A-CO-CH2-Hal(IV))立体特异性合成对应的顺式或反式乙酮肟(式IIc或IIt)。制备顺式乙酮肟(IIc)时,首先将其与咪唑或适当取代的衍生物反应,然后在高温下与羟胺反应,同时加入过量的碱;制备反式乙酮肟(IIt)时,首先在温和条件下与羟胺反应,然后在冷却时与咪唑或适当取代的衍生物反应。产品是有效的杀菌剂或细菌剂,因此在人类和兽医学领域中用作热疗剂,也用作农业和园艺中的杀菌剂。