| abstract |
The present invention relates to a synthesis method of 3-(α-methoxy)methenylbenzofuran-2(3H)-one, the steps include: synthesis of o-hydroxyphenylacetic acid, synthesis of lactone, synthesis of final product, key improvements It lies in the synthesis of lactone, so that the three-step reaction can be carried out in series without separating and purifying the intermediate o-hydroxyphenylacetic acid and lactone; the steps include: removing acid water from the filtrate of the synthetic o-hydroxyphenylacetic acid at pH=1; acetic acid catalyzed reaction , azeotropic distillation to remove the water generated by the reaction until no more water is generated in the system; cooling to precipitate sodium chloride, filtering, and washing the solid with toluene; combining the filtrate and washing liquid, and concentrating under reduced pressure to recover the residue after toluene and catalyst acetic acid Then react with trimethyl formate and acetic anhydride to obtain the final product; use acetic acid as a catalyst, do not react with sodium chloride, filter to remove sodium chloride after the reaction is completed, and then distill toluene and acetic acid under reduced pressure without neutralization and washing processes. No waste water is produced and no drying process is required. |