Compounds having the formula R.sup.5 O--A--NR.sup.4 --R.sup.2 (V) where R.sup.2 is a heteroaryl group linked to the remainder of the molecule via a carbon atom adjacent a nitrogen atom and R.sup.4 and R.sup.5 are both hydrogen atoms or together represent --SO-- or --SO.sub.2 -- and A is C.sub.2 -C.sub.4 alkylene optionally substituted by one or more lower alkyl groups are novel intermediates in the preparation of pharmaceutically useful piperazine derivatives as end compounds. The compounds having formula V where R.sup.4 and R.sup.5 are hydrogen may be prepared by a rearrangement of a compound having the formula (VI). R.sup.2 O--A--NH.sub.2 (VI)
具有公式R.sup.5 O--A--NR.sup.4 --R.sup.2(V)的化合物,其中R.sup.2是杂环基团,通过与分子余部相连的氮原子相邻的碳原子连接,并且R.sup.4和R.sup.5均为氢原子或共同表示为--SO--或--SO.sub.2--,而A是C.sub.2-C.sub.4烷基,可选择地被一个或多个较低的烷基取代,是制备作为最终化合物的医药上有用的
哌嗪衍
生物的新中间体。具有公式V的化合物,其中R.sup.4和R.sup.5为氢,可以通过具有公式(VI)的化合物的重排来制备。R.sup.2 O--A--NH.sub.2(VI)