Yield:-

Reaction Conditions:

Stage #1:2-Fluoroaniline with sulfuric acid;dihydrogen peroxide;bromine at 10 - 15; for 0.5 h;
Stage #2: with nitrosylsulfuric acid at 5; for 2 h;Overall yield = 80.8 %;

Steps:

5.1
(1) In parts by weight, 100 parts of 60% sulfuric acid and 20 parts of o-fluoroaniline were added to the reaction kettle, and the temperature was lowered to 10 ° C while stirring, and 16 parts of bromine was slowly added dropwise, and the dropwise addition was completed. Slowly raise the temperature to 15 ° C, keep warm and add 12 parts of 35% hydrogen peroxide, react at constant temperature for 30 min, cool down again to 5 ° C, keep warm and add 5.5 parts of 40% nitrosyl sulfate, keep the reaction for 2 h, slowly heat up to 40 ° C, heat and add 34 parts of a mixture of isopropanol and water, wherein the mixture of isopropanol and water in the mass ratio of isopropanol to water is 13:100, after the end of the addition, stirring for 1 h, and then warmed to At 60 ° C, the temperature was kept for 1 h, and the layer was allowed to stand to separate the water layer and the oil layer. (2) Put the oil layer in the rectification equipment, firstly heat up to 70 ° C, heat for 5 min, then raise the temperature to 83 ° C at a rate of 0.5 ° C / min, and rectify and separate to obtain m-fluorobromobenzene and 3, 5-dibromofluorobenzene. (3) The aqueous layer is distilled at 90 ° C to separate a low boiling point isopropanol, a mixture of water and acetone and 60% sulfuric acid, and 60% of the sulfuric acid can be used for recycling as a raw material of m-fluorobromobenzene and as a raw material. Raw material of nitrosylsulfuric acid. (4) The silica mashed sieve is divided into micron-sized granules. After drying, it is added to an equal volume of an aqueous solution containing active components of nickel, cobalt, uranium and copper, and heated at 30 ° C for 4 h, then dried, at 450 Baking at a high temperature for 3 h at °C, a silica supported catalyst supporting nickel, cobalt, platinum and copper is obtained. The content of nickel in the silica supported catalyst supporting nickel, cobalt, platinum and copper is 7%, and the content of copper is The content of cobalt was 2.5%, and the content of platinum was 1%. After the silica-supported catalyst supporting nickel, cobalt, platinum and copper is activated by hydrogen, a mixture of isopropanol, water and acetone is added, and the mixture of isopropanol, water and acetone is fed at a rate of 30 mL/h. Hydrogen was introduced at a hydrogen to feed ratio of 6:1, and catalytic hydrogenation was carried out at 260 ° C and 3.5 MPa to obtain a mixture of isopropanol and water.

References:

Zhejiang Jieshi New Materials Co., Ltd.;Xie Weiyu;Xu Zhou CN108821935, 2018, A Location in patent:Paragraph 0025-0056

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