申请人:Thomas C. Elder, Inc.
公开号:US04216154A1
公开(公告)日:1980-08-05
.alpha.-Loweralkylfurocoumarins are produced by forming a .beta.-haloalk-2-enyl, e.g., .beta.-haloallyl, ether of a hydroxycoumarin having an active hydrogen in the position ortho to the hydroxy group, and heating the formed ether, preferably in dimethylaniline or like basic amine solvent. An abnormal Claisen rearrangement produces a novel o-hydroxy-(.beta.-haloalk-2-enyl) coumarin intermediate which can be dehydrohalogenated directly without isolation to the desired .alpha.-loweralkylfurocoumarin, e.g., .alpha.-methylfurocoumarin.
α-较低烷基呋喃香豆素是通过形成一个β-卤代烷基,例如β-卤代烯丙基,羟基香豆素的醚化合物来制备的,其中羟基的邻位具有活性氢,并且加热所形成的醚化合物,最好在二甲基苯胺或类似的碱性胺溶剂中进行。一种异常的克莱森重排产生了一种新型的o-羟基-(β-卤代烯丙基)香豆素中间体,可以直接脱卤化而不需要分离,得到所需的α-较低烷基呋喃香豆素,例如α-甲基呋喃香豆素。