Molecular Formula | C5H5BFNO2 |
Molar Mass | 140.91 |
Density | 1.34±0.1 g/cm3(Predicted) |
Melting Point | 177-178°C (dec.) |
Boling Point | 311.5±52.0 °C(Predicted) |
Flash Point | 151.5°C |
Vapor Presure | 8.55E-05mmHg at 25°C |
BRN | 8974962 |
pKa | 6.97±0.10(Predicted) |
Storage Condition | Keep in dark place,Sealed in dry,Room Temperature |
Refractive Index | 1.507 |
MDL | MFCD03411559 |
Hazard Symbols | Xi - Irritant |
Risk Codes | 36/37/38 - 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. S36 - Wear suitable protective clothing. S36/37 - Wear suitable protective clothing and gloves. |
WGK Germany | 3 |
HS Code | 29349990 |
Hazard Class | IRRITANT |
introduction | 2-fluoro -5-pyridine boronic acid has a melting point of 177-178°C (dec.), a boiling point of 311.5±52.0°C(Predicted), and a density of 1.34±0.1 g/cm3(Predicted). The acidity coefficient is 6.97±0.10(Predicted). |
synthesis method | n-butyl lithium (15% hexane, 3.6 mL, 5.76 mmol, 1.2 equivalent) is added to dry ether (5 mL) and cooled to -78 ℃ in N2 atmosphere. Drop addition of dry ether (3 mL) solution of 5-bromo-2-fluoropyridine (0.5 mL, 4.86 mmol, 1 equivalent), and the obtained yellow precipitate was stirred at -78 ℃ for 45 minutes. Add trimethylborate (0.66 mL, 5.83 mmol, 1.2 the same amount), the reaction is heated to room temperature, and then stirred for 1 hour. The reaction mixture was treated with 5% aqueous sodium hydroxide (25 mL), cooled in ice, and acidified with 3m hydrochloric acid until neutral pH (universal indicator paper). The solution was extracted with ethyl acetate (3x50 mL), combined with organic phase, and dried with MgSO4. The solvent was removed by reduced pressure evaporation to obtain a brown-yellow solid, and 3.85 (456 mg, 73%) 2-fluoro-5-pyridine boronic acid was obtained by washing with 10% ethyl acetate/petroleum ether. The melting point is 190-191 degc. |