Compounds of the formula (I) ##STR1## and salts and pro-drugs thereof, wherein: R.sub.1 is a hydrogen atom or a lower alkyl group; R.sub.2 is a hydrogen atom or a lower alkyl group; R.sub.3 is a hydrogen atom or a lower alkyl group; R.sub.4 is a hydrogen atom or an alkyl group; R.sub.5 is a lower alkyl or a substituted alkyl group; or R.sub.4 and R.sub.5 are joined so that together with the nitrogen atom to which they are attached they form a 5-, 6- or 7-membered ring optionally containing an oxygen or sulphur atom; R.sub.6 is an electron donating group; R.sub.7 is an electron withdrawing group; and the NR.sub.4 R.sub.5 and OR.sub.3 moieties are trans having compositions containing them and processes for their preparation.
化合物的分子式(I)##STR1##及其盐和前药,其中:R.sub.1是氢原子或低碳基团;R.sub.2是氢原子或低碳基团;R.sub.3是氢原子或低碳基团;R.sub.4是氢原子或烷基团;R.sub.5是低碳基或取代烷基团;或者R.sub.4和R.sub.5相连,使它们与它们附着的氮原子一起形成一个含有氧或
硫原子的5、6或7元环;R.sub.6是电子给体基团;R.sub.7是电子受体基团;以及含有NR.sub.4 R.sub.5和OR.sub.3基团的组合物及其制备方法。