A common heterocyclic compound, 444-14-4, name is 2-Bromo-4,6-difluoroaniline, molecular formula is C6H4BrF2N, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 444-14-4.
3. Amination The 1-bromo-3,5-difluorobenzene generated by diazotization of 2-bromo-4,6-difluoroaniline can be converted to 100 lbs. of 3,5-difluoroaniline as follows: A suitable pressure reactor designed for a minimum of 300 psig pressure is charged with 288.1 lbs. of 29% aqueous ammonia. The reactor is designed to provide for pressure control via temperature control of the reaction. To the ammonia charge, 4.7 lbs. of cuprous oxide is added, and the 168.2 lbs. of crude 1-bromo-3,5-difluorobenzene product is added. The reaction mixture is heated to about 135 C. using temperature control to maintain a maximum pressure of 300 psig, and the reaction pressure is maintained at about 300 psig by slowly increasing the reaction temperature to 165 C. over 4.5 hours. The reaction mixture is held at 165 C. for one additional hour, and then a sample is assayed for completeness of the reaction. If more than 0.5% by weight of 1-bromo-3,5-difluorobenzene remains unreacted, then the reaction mixture is held at 165 C. for one more hour and re-assayed. This process is repeated until less than 0.5% by weight of unreacted 1-bromo-3,5-difluorobenzene remains.
The synthetic route of 2-Bromo-4,6-difluoroaniline has been constantly updated, and we look forward to future research findings.
Reference:
Patent; BASF Corporation; US5977412; (1999); A;,
Bromide – Wikipedia,
bromide – Wiktionary