1,3-dibromo-4-fluorobenzene preparation method

A technology of fluorobenzene and o-fluoronitrobenzene is applied in the field of preparation of 1,3-dibromo-4-fluorobenzene, and can solve the problems of complicated subsequent separation, short process route and the like

Inactive Publication Date: 2019-02-19
CHANGZHOU UNIV
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Problems solved by technology

Another synthetic method is to use 2,5-difluorobenzoic acid as a raw material, nitrate with mixed acid, and then add bromine to bromine, with a total yield of 27%. Although the process route is short, subsequent separation is very cumbersome (Bioorganic & Medicinal Chemistry Letters, 2006, 16(20), 5392-5397; PCT2004069832)

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  • 1,3-dibromo-4-fluorobenzene preparation method

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specific Embodiment approach 2

[0018] (1) Bromination reaction: Add 1,200 g of o-fluoronitrobenzene and 6,000 mL of acetic acid as a solvent into the reaction vessel, control the temperature at about 15 degrees, and add 1,680 g of brominated reagent N-bromosuccinimide in batches. After the addition, stir for a period of time, GC tracking, until the reaction is complete. After the reaction was completed, it was analyzed with ice water and filtered with suction to obtain 1808 g of off-white solid 5-bromo-2-fluoronitrobenzene with a purity of 97% and a yield of 96.3%.

[0019] (2) Reduction reaction: Add 1420 g of iron powder and an appropriate amount of water into the reactor, stir, heat, control the temperature at about 90 degrees, and then add 1320 g of the nitro substance in the previous step in batches. After adding, GC traces until the reaction is complete. After the reaction was completed, cool, add ethyl acetate, filter with suction, separate the oil layer from the mother liquor, and rotary evaporate ...

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Abstract

The invention discloses an industrial preparation method of 1,3-dibromo-4-fluorobenzene. The industrial preparation method of 1,3-dibromo-4-fluorobenzene comprises the steps that o-fluoronitrobenzeneserves as an initial raw material, and 1,3-dibromo-4-fluorobenzene is synthesized through bromine applying, reduction and diazotization-Sandmeyer three step reactions. The obtained 1,3-dibromo-4-fluorobenzene is yellow oily liquid, the purity is 97.5%, the raw material conversion rates of all steps each reach 100%, and the total recovery of the whole process reaches 52.7%.

Description

technical field [0001] The invention relates to a production method of a pharmaceutical intermediate, in particular to a production method of 1,3-dibromo-4-fluorobenzene. Background technique [0002] At present, 1,3-dibromo-4-fluorobenzene is mainly used in the pharmaceutical industry. For example, it can be used for: 1) synthesis of antibacterial drug tricyclic substituted oxazolone and its derivatives 2) synthesis of new antibacterial drug phenproheptanone 3) synthesis of peptide-containing macrocyclic proline as an inhibitor of hepatitis C . [0003] At present, there are two methods for the synthesis of the target compound. Romero (PCT 2016055028) introduced a method of directly adding bromine to 2,5-difluoronitrobenzene to synthesize the target compound, and the yield was only 23%. Another synthetic method is to use 2,5-difluorobenzoic acid as a raw material, nitrate with mixed acid, and then add bromine to bromine, with a total yield of 27%. Although the process rou...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/093C07C25/13
CPCC07C17/093C07C201/12C07C209/365C07C25/13C07C211/52C07C205/12
Inventor 陈兴权董燕敏
Owner CHANGZHOU UNIV
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