公开(公告)号：US5659051A

公开(公告)日：1997-08-19

申请号：US273119

申请日：1994-07-11

申请人： Takayuki Higashii ,  Hideki Ushio ,  Yukari Fujimoto ,  Tsutomu Matsumoto ,  Masayoshi Minai ,  Katsuichi Yasunaga ,  Hiroshi Sogabe ,  Takahiro Kotera

发明人： Takayuki Higashii ,  Hideki Ushio ,  Yukari Fujimoto ,  Tsutomu Matsumoto ,  Masayoshi Minai ,  Katsuichi Yasunaga ,  Hiroshi Sogabe ,  Takahiro Kotera

IPC分类号： C07D311/24

CPC分类号： C07D311/24

摘要： There is disclosed a process of producing a 2-cyano-4-oxo-4H-benzopyran compound of the general formula (2): ##STR1## wherein R.sup.1 and R.sup.2 are independently hydrogen, halogen, hydroxy, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy, nitro or a group of the RCONH wherein R is C.sub.1 -C.sub.20 alkyl, phenyl, phenyl-substituted (C.sub.1 -C.sub.20) alkyl, phenyl (C.sub.1 -C.sub.20)alkoxyphenyl or (C.sub.1 -C.sub.20) alkoxyphenyl. This production process is characterized in that a carboxamide of the general formula (1): ##STR2## wherein R.sup.1 and R.sup.2 are each as defined above, is reacted with a dehydrating agent in the presence of a pyridine compound of the general formula (4): ##STR3## wherein A.sup.1 and A.sup.2 are independently hydrogen or C.sub.1 -C.sub.5 alkyl. If the final product cannot be obtained as crystals having good filtration properties by ordinary treatments, a novel technique as disclosed herein can provide such crystals by dissolving the reaction product in an organic solvent insoluble or slightly soluble in water; pouring the resultant solution into water; and removing the organic solvent by distillation with stirring to effect the crystallization of the final product.

摘要翻译： 公开了通式（2）的2-氰基-4-氧代-4H-苯并吡喃化合物的制备方法：其中R 1和R 2独立地是氢，卤素，羟基，C 1 -C 5烷基 硝基或其中R为C 1 -C 20烷基，苯基，苯基取代的（C 1 -C 20）烷基，苯基（C 1 -C 20）烷氧基苯基或（C 1 -C 20）烷氧基苯基）的RCONH基团。 该制造方法的特征在于通式（1）的羧酰胺：其中R 1和R 2各自如上所定义，与脱水剂在通式（Ⅴ）的吡啶化合物存在下反应， （4）：其中A1和A2独立地为氢或C1-C5烷基。 如果通过常规处理不能获得具有良好过滤性能的结晶的最终产品，则本文公开的新技术可以通过将反应产物溶解在不溶或微溶于水的有机溶剂中来提供这种晶体; 将所得溶液倒入水中; 并在搅拌下通过蒸馏除去有机溶剂以实现最终产物的结晶。