Trimethyltin chloride → HCID 18314853, compound

1-bromo-3,5-difluorobenzene (38.6 g, 0.2 mol) was added slowly to a mixture of magnesium turnings (4.8 g, 0.2 mol) in 200 ml anhydrous ethyl ether. After the reaction mixture was refluxed for 2 hrs, trimethyltin chloride (40 g, 0.2 mol) was dropped in to the solution and kept refluxing for one more hour. Then the reaction mixture was hydrolyzed by saturated ammonium chloride. The organic layer of 3,5-difluorophenyltrimethyltin was separated and purified by distillation in a 62% yield. Then the 3,5-difluorophenyltrimethyltin (11 g, 0.04 mol) was reacted with boron trichloride (11 g, 0.093 mol) in a sealed tube at 0° C. for 1 hr and at room temperature for 12 hrs. Dichloro-3,5-difluorophenylborane (6.3 g, 0.032 mol) was obtained from the reaction in 81% yield. Dichloro-3,5-difluorophenylborane (5.84 g, 0.03 mol) was added into a solution containing perfluoropinacol (10 g, 0.03 mol) in 50 ml anhydrous chloroform at −40° C. Then the reaction mixture was stirred continuously at room temperature for 4 hrs. Then the insoluble material was filtered off from the solution. The chloroform solvent was removed by evaporation. The pure product compound 4 (10 g, 0.022 mol) was obtained by distillation of the residue in 73% yield. Boiling point: 80° C./14 mm-Hg. NMR (CDCl3 ppm) δ: 6.9-7.4 (m, 1H), 7.35-7.7 (m, 2H). IR (neat cm−1), ν 3092.0, 1593.8, 1480.6, 1432.0, 1388.2, 1248.9, 1109.8, 1080.5, 986.9, 952.8, 889.6, 870.4, 748.2, 721.8.

1. temperatureAfter the reaction mixture was refluxed for 2 hrs
2. temperaturekept refluxing for one more hour
3. customThe organic layer of 3,5-difluorophenyltrimethyltin was separated
4. distillationpurified by distillation in a 62% yield

ORD record

ord-28b3bac24cd748c68815407329e91958

Source dataset

uspto-grants-2002_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06352798B1