Molecular Formula | C7H6BrF |
Molar Mass | 189.02 |
Density | 1.494 g/mL at 25 °C (lit.) |
Boling Point | 95 °C/50 mmHg (lit.) |
Flash Point | 95°F |
Appearance | Liquid |
Specific Gravity | 1.494 |
Color | Clear light yellow |
BRN | 2500154 |
Storage Condition | Sealed in dry,Room Temperature |
Refractive Index | n20/D 1.53(lit.) |
Physical and Chemical Properties | Colorless or light yellow liquid |
Hazard Symbols | Xi - Irritant |
Risk Codes | R10 - Flammable R36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S37/39 - Wear suitable gloves and eye/face protection S16 - Keep away from sources of ignition. |
UN IDs | UN 1993 3/PG 3 |
WGK Germany | 3 |
HS Code | 29039990 |
Hazard Note | Irritant |
Hazard Class | 3 |
Packing Group | III |
introduction | 4-bromo-3-fluorotoluene belongs to 4-halo-3-fluorotoluene (I), which is an organic synthesis intermediate, especially as an intermediate for preparing drugs, and has a wide range of applications. |
preparation | 3-fluorotoluene (111g,99.0%), dichloroethane (300mL) and iron powder (5.7g) are sequentially injected into the reaction bottle, stirring is started, the temperature is controlled at 30-35 ℃, bromine (353.8g) is added dropwise, the dropwise is finished in about 4 hours, stirring for 6 hours after dropwise, sampling and analysis, after qualified, add water (100g), stir for 0.5 hours, then stand for stratification, add water (100g) and anhydrous sodium sulfite (5g) to the lower organic layer, stir for 0.5 hours, then stand for stratification, and the organic phase is concentrated under reduced pressure to obtain light yellow oil (267g). GC analysis shows that the content of 2,4-dibromo -5-fluorotoluene is 85%, and the content of 2,6-dibromo -3-fluorotoluene is 13%. The mixture of 2,4-dibromo-5-fluorotoluene and 2,6-dibromo-3-fluorotoluene (267g) prepared above was put into an autoclave, and methanol (400mL), sodium acetate (124g), palladium carbon (0.8g, palladium content 5%, moisture content 60%) were added. The autoclave is sealed, the air in the autoclave is replaced, hydrogen is introduced to pressurize to 2.2MPa, the temperature is raised to 75~80 ℃, the hydrogen pressure is maintained to be 1.8~2.2MPa, the heat preservation reaction is carried out for 10 hours, the temperature is reduced and the pressure is relieved. The reaction mixture is removed from the autoclave, filtered, the mother liquor is rectified under normal pressure, and the fraction is collected as methanol at 62 to 64 degrees C. When the top temperature of the distillation tower drops to 61 degrees C, the heating is stopped and reduced to room temperature, water (150g) is added, and the mixture is fully stirred and stratified. 183g of yellow oil is obtained. The resulting yellow oily mixture was subjected to atmospheric distillation, and the fraction was collected as 3-fluorotoluene at 113-115°C, and when the top temperature of the tower dropped to 112°C, it was reduced to room temperature, the vacuum pump was turned on, and the residue in the distillation reaction bottle was subjected to vacuum distillation (vacuum 40-41mmHg), the fraction was collected as 2-bromo-5-fluorotoluene at 81-83°C, and the fraction was collected as 4-bromo-3-fluorotoluene at 84-86°C; the specific results of each component collected are as follows: the fraction collected at 113-115 ℃ is 3-fluorotoluene, 25.2g, and the content is 98.9%; The fraction collected at 81-83 ℃ is 2-bromo -5-fluorotoluene, 35.0g, with a content of 98.9%; The fraction collected at 84-86 ℃ is 4-bromo -3-fluorotoluene, 90.5g, with a content of 98.8%. The mixture of 3-fluorotoluene, 2-bromo-5-fluorotoluene and 2,6-dibromo-5-fluorotoluene and 2,6-dibromo-3-fluorotoluene, the mixture of 2,4-dibromo-5-fluorotoluene and 2,6-dibromo-3-fluorotoluene (53.6g) is put into an autoclave, and the 75% ethanol aqueous solution (m/m,150g), sodium acetate (24.8g), tetrabutylammonium bromide (0.2g), palladium carbon (0.5g, palladium content 5%, moisture content 60%). The autoclave is sealed, the air in the autoclave is replaced, hydrogen is introduced to pressurize to 0.5MPa, the temperature is raised to 75~80 ℃, the hydrogen pressure is maintained to be 0.4~0.5MPa, the heat preservation reaction is carried out for 10 hours, the temperature is reduced and the pressure is relieved. GC analysis The content of 3-fluorotoluene in the reaction mixture is 25.2%, the content of 2-bromo-5-fluorotoluene is 18.4%, the content of 4-bromo-3-fluorotoluene is 41.4%, the content of 2, 4-dibromo-5-fluorotoluene is 10.2%, and the content of 2, 6-dibromo-3-fluorotoluene is 3.6%. Then the reaction mixture is rectified to obtain the target product 4-bromo-3-fluorotoluene. |