Synthetic method for 4- trifluoromethyl-2- trifluoromethyl

Abstract

The invention discloses a synthetic method for 4-trifluoromethyl-2-trifluoromethyl. The method includes choosing L-hydroxyproline as a starting material, using Boc and Bn for protecting imidogen and carboxyl respectively, generating an intermediate (2S, 4R)-N-Boc-4-hydroxyproline benzyl ester; obtaining an intermediate (2S)-N-Boc-4-pidolic acid benzyl ester through 2-IBX oxidative hydroxyl; reacting TMSCF3 with the (2S)-N-Boc-4-pidolic acid benzyl ester and introducing trifluoromethyl; obtaining an intermediate N-Boc-4-trifluoromethyl-2-pyrrole carboxylic acid benzyl ester through thionyl chloride dehydration and chromium trioxide oxidation; and obtaining the 4-trifluoromethyl-2-trifluoromethyl through removing of a protecting group by hydrogen chloride and palladium hydroxide on activated carbon.

Description

technical field [0001] The invention relates to a synthesis method of 4-trifluoromethyl-2-pyrrolecarboxylic acid, which belongs to the field of organic synthesis. Background technique [0002] In recent years, the wide application of fluorinated heterocyclic compounds in medicine, pesticides and new materials has aroused great interest of organic compound scientists. Recently, there have been many reports on the synthesis methods of fluorinated heterocyclic compounds. 4-trifluoromethylpyrrole derivatives are a very important class of fluorine-containing heterocyclic compounds, and 4-trifluoromethyl-2-pyrrolecarboxylic acid is an important intermediate for the preparation of 4-trifluoromethylpyrrole derivatives. [0003] In the synthesis of trifluoromethyl heterocyclic compounds, the commonly used methods are to convert functional groups such as carboxyl groups in heterocyclic molecules into trifluoromethyl groups or to introduce trifluoromethyl groups on heterocyclic skeleto...

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Problems solved by technology

[0003] In the synthesis of trifluoromethyl heterocyclic compounds, the commonly used methods are to convert functional groups such as carboxyl groups in heterocyclic molecules into trifluoromethyl groups or to introduce trifluoromethyl groups on heterocyclic skeletons through trifluoromethylation reactions. The method is limited due to severe reaction conditions, low reaction yield and the disadvantages of generally expensive and highly toxic reagents.

Both Luo Yongrong's research group and Zeng Qingbin's research group synthesized trifluoromethylpyrrole and its related trifluoromethyl heterocyclic compounds using trifluoromethyl oxazolone as the starting material. The reaction conditions of this method are strict and are not conducive to industrialization. Production

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