Zhejiang Xianfeng Technologies Co., Ltd.

With the development of reform and opening up, China′s economic strength has been continuously enhanced, people′s living standards have improved significantly, and material and cultural needs have become higher and higher.In order to better meet people′s needs and the needs of social development, people have new requirements for the chem. industry.In this context, the paper mainly studies the phase transfer catalysis in organic synthesis.Firstly, based on the theor. basis, the transformation principle and reaction conditions are expounded, and the application in organic synthesis is listed.It is hoped that through the discussion of this paper, the application of phase transfer catalysis in organic synthesis can be promoted, and it can also provide reference for related industries.

In this work, the related impurities A, D, G and H of ondansetron hydrochloride in EP 9.0 were synthesized for the first time.2,3-Dihydro-1H-carbazol-4(9H)-one and 9-methyl-2,3-dihydro-1H-carbazol-4(9H)-one were used as starting materials resp.At first, the starting material reacted with paraformaldehyde and dimethylamine hydrochloride.Impurities A and D were obtained via this Mannich reaction.Then the products in the first step reacted with imidazole or 2-methylimidazole and gave impurities G and H.The synthesis method was easy to operate and afforded the impurities with high yields.

To perform the quality control of lovastinib, 4-amino-3-chlorophenol was used as the starting material to obtain the intermediate 1-(2-chloro-4-hydroxyphenyl)-3-cyclopropylurea () via the reaction of acylation and urea formation, and then with 4-Chloro-7-methoxyquinoline-6-carboxamide () undergoes nucleophilic substitution reaction to obtain the related impurity of lenvatinib: 4, 4′-[ 4, 4′-carbonyl bis (urea) Bis (3-chloro-4, 1-phenylene) ] bis (oxy) bis (7-methoxyquinoline-6-carboxamide) .The impurity is a process impurity and its structure is confirmed by confirmed by NMR, MS and elemental anal.At the same time, the causes and mechanisms of the impurities were analyzed to provide guidance for the industrial production of levartinib in the future.