The present invention provides a process for producing a 2-acylthiophene compound which has a low content of the 3-isomer generated as a by-product, the process comprising reacting a thiophene compound represented by formula (1):
wherein R
1
is a hydrogen atom, a C
1-6
alkyl group, a phenyl group, or a halogen atom, with at least one member selected from the group consisting of acid anhydrides represented by formula (2):
wherein R
2
is a C
1-6
alkyl group or a phenyl group, and acid halides represented by formula (3):
wherein R
2
is as defined above and X is a halogen atom, in the presence of a solid acid catalyst at a temperature less than 75° C. in the absence of solvent, thus producing a 2-acylthiophene compound represented by formula (4):
wherein R
1
and R
2
are as defined above.
本发明提供了一种制备2-酰基
噻吩化合物的方法,其副产物3-异构体的含量较低。该方法包括在无溶剂存在的情况下,在固体酸催化剂的存在下,将由式(1)表示的
噻吩化合物与由式(2)表示的酸酐和/或由式(3)表示的酸卤化物中至少一种进行反应,其中R1是氢原子,C1-6烷基,苯基或卤素原子之一,R2是C1-6烷基或苯基,X是卤素原子,反应温度低于75°C,从而产生由式(4)表示的2-酰基
噻吩化合物,其中R1和R2如上所定义。