A process for the preparation of 2H-3-isoquinolones having the formula ##SPC1## Wherein R.sub.1 and R.sub.2 are each hydrogen, halogen, lower alkyl, lower alkoxy, aryl, haloaryl, alkylaryl or alkoxyaryl; R.sub.3 and R.sub.4 are each hydrogen, lower alkyl, lower alkoxyalkyl, lower alkenyl, lower alkynyl, cycloalkyl, aryl, aralkyl, or halo-aralkyl, which comprises cyclizing an N-formyl-2-phenyl-acetamide of the formula ##SPC2## Wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 have the same meaning as above, with a cyclodehydration agent. Said 2H-3-isoquinolones are useful as starting materials e.g. in the synthesis of 1,4-dihydro-1,4-etheno-isoquinolin-3(2H)-ones which are valuable chemotherapeutic agents in the treatment of disorders of the central nervous system, such as troubles of wakefulness, disorders of equilibrium and vertigo.
一种制备具有以下式子的2H-3-
异喹啉酮的过程:##
SPC1##
其中R.sub.1和R.sub.2分别为氢、卤素、较低的烷基、较低的烷氧基、芳基、卤代芳基、烷基芳基或烷氧基芳基;R.sub.3和R.sub.4分别为氢、较低的烷基、较低的烷氧基烷基、较低的烯基、较低的炔基、环烷基、芳基、芳基烷基或卤代芳基烷基,该过程包括将上述式子中R.sub.1、R.sub.2、R.sub.3和R.sub.4具有相同含义的N-甲酰基-2-苯基乙酰胺与环缩脱
水剂环化。所述2H-3-
异喹啉酮可用作起始材料,例如在合成1,4-二氢-1,4-
乙烯-
异喹啉-3(2H)-酮方面,该化合物是治疗中枢神经系统疾病的有价值的化疗药物,例如清醒障碍、平衡障碍和眩晕等。