Georgiadis M P
J Med Chem. 1976 Feb;19(2):346-9. doi: 10.1021/jm00224a033.
A Michael type addition of an amine to 6-methoxy-2-methyl-2-(4'-biphenylyl)-2H-pyran-3(6H)-one (1) dissolved in ether, benzene, or THF gave 5-amino derivatives of 5,6-dihydro-6-methoxy-2-methyl-2-(4'-biphenylyl)-2H-pyran-3(4H)-one (2). These by subsequent reduction with LiAlH4 were converted to 5-amino derivatives of 6-methoxy-2-methyl-2-(4'-biphenylyl)tetrahydro-2H-pyran-3-ol (3). Both isomers A and B of 1 (in regard to the methoxy group at C6) were used for the synthesis of 2 and 3. The in vitro antimicrobial activity of the amine adducts 2 was of the same order of magnitude as the starting material. Amine adducts in general, however, were by far more active as coccidiostats than the starting material and retained their activities when they were reduced. 5,6-Dihydro-6-methoxy-2-methyl-2-(4'-biphenylyl)-5-(dimethylamino)-2H-pyran-3(4H)-one hydrochloride (A) and 5,6-dihydro-6-methoxy-2-methyl-2-(4'-biphenylyl)-5-(dimethylamino)-2H-pyran-3(4H)-one hydrochloride (B), prepared from isomer A and B of 1, respectively, were the most active as coccidiostats. These compounds when administered orally to chickens 1 day prior to infection at a concentration 0.05% in their diet gave them total protection against Eimeria tenella.
将胺与溶解在乙醚、苯或四氢呋喃中的6-甲氧基-2-甲基-2-(4'-联苯基)-2H-吡喃-3(6H)-酮(1)进行迈克尔型加成反应,得到5,6-二氢-6-甲氧基-2-甲基-2-(4'-联苯基)-2H-吡喃-3(4H)-酮(2)的5-氨基衍生物。随后用氢化铝锂将这些产物还原,转化为6-甲氧基-2-甲基-2-(4'-联苯基)四氢-2H-吡喃-3-醇(3)的5-氨基衍生物。1的异构体A和B(关于C6处的甲氧基)均用于2和3的合成。胺加成物2的体外抗菌活性与起始原料处于同一数量级。然而,一般来说,胺加成物作为抗球虫剂的活性远比起始原料高,并且在还原后仍保留其活性。分别由1的异构体A和B制备的5,6-二氢-6-甲氧基-2-甲基-2-(4'-联苯基)-5-(二甲氨基)-2H-吡喃-3(4H)-酮盐酸盐(A)和5,6-二氢-6-甲氧基-2-甲基-2-(4'-联苯基)-5-(二甲氨基)-2H-吡喃-3(4H)-酮盐酸盐(B)作为抗球虫剂活性最高。在感染前1天,以0.05%的浓度将这些化合物添加到鸡的饲料中口服给药,可使鸡完全抵御柔嫩艾美耳球虫。