ChemicalBook CAS DataBase List 1,2,3-Trifluoro-4-nitrobenzene

1,2,3-Trifluoro-4-nitrobenzene synthesis

11synthesis methods

Product Name:1,2,3-Trifluoro-4-nitrobenzene
CAS Number:771-69-7
Molecular formula:C6H2F3NO2
Molecular Weight:177.08

17700-09-3

771-69-7

General procedure for the synthesis of 2,3,4-trifluoronitrobenzene from 2,3,4-trichloronitrobenzene: (2) 240 g of DMSO and 120 g of 2,3,4-trichloronitrobenzene were added to an anhydrous reaction flask with stirring turned on, and the temperature was raised to 75-80 °C under reduced pressure with continuous stirring for 2 hours. Subsequently, 76.8 g of KF and 12 g of TBAB were added to the reaction system and dehydrated under reduced pressure at 75-80 °C for 2 h until no droplets of water fell from the distillation head. (3) The reaction system was slowly warmed up to 180 °C to start the reaction. The reaction process was monitored by gas chromatography (GC), and the reaction was completed when the content of both 2-fluoro-3,4-dichloronitrobenzene and 2,3-dichloro-4-fluoronitrobenzene decreased to less than 0.2% after 10 h. The reaction was completed when the content of 2-fluoro-3,4-dichloronitrobenzene and 2,3-dichloro-4-fluoronitrobenzene dropped below 0.2%. The reaction mixture was cooled to 70-75 °C, filtered, and the filtrate was vacuum distilled and reintroduced into the anhydrous reaction unit. 46 g of KF and 12 g of TBAF were added and dehydrated under reduced pressure at 75-80 °C for 2 h until no water droplets appeared in the distillation head. The reaction temperature was set to 120 °C and ultrasonic power to 20 kHz and the reaction was continued. The reaction was monitored by GC and completed after 2 hours. The reaction mixture was cooled to 70-75°C and filtered and the filtrate was distilled to separate DMSO from the product. The final yield of 2,3,4-trifluoronitrobenzene was 99.7%.

2268-05-5 Synthesis

2268-05-5
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771-69-7
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Yield:771-69-7 85.5%

Reaction Conditions:

Stage #1:1,3-dichloro-2-fluorobenzene with sulfuric acid;nitric acid at 20 - 25; for 2.5 h;
Stage #2: with sulfolane;potassium fluoride for 5 h;

Steps:

10 Example 10
n a 250 ml four-necked flask, 64 g of 98% concentrated sulfuric acid was charged(0.606 mol) of 2,6-dichlorofluorobenzene was added dropwise to a stirred solution of 33 g of 98% concentrated sulfuric acid at 20 to 25 ° CMixed with 39 g of 98% concentrated nitric acid, 2.5 hThe addition is complete.After warming up to 40 ~ 45 ° C and heat 1.5 hours. After the end of the washing, to neutral, organic subtractionPressure dehydration after use.In a 250 ml four-necked flask285gSulfolane and87g (1.5mol) KF, after dehydration by adding the last step nitration products,In 195 ± 5 ° C heat 5h, vacuum distillation of the solvent and then distillation 2,3,4-trifluoronitrobenzene 91. 7g,The content was 99.8% and the yield was 85.5%

References:

Binhai Yongtai Medical Chemical Co Ltd;He, Renbao;Shao, Hongming CN102249881, 2016, B Location in patent:Paragraph 0015; 0057-0059

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393-79-3 Synthesis