Isoamyl Nitrite → HCID 86616976, compound

To a suspension of 12.00 g (0.033 mol) 5-bromo-3-(4-chloro-phenyl)-pyrazin-2-ylamine in 80 ml dibromomethane was added 5.93 g isoamyl nitrite. To the resulting mixture was added dropwise during ca 45 min a solution of 7.75 g trimethylbromosilane in 20 ml dibromomethane with stirring at ambient temperature. The mixture was stirred at room temperature for 2 h. To the resulting dark solution was added 100 ml of a 10% aqueous sodium bicarbonate. The phases were separated and the organic phase washed with brine. To the organic phase was added silica gel (ca. 100 g) and the solvent was removed under aspirator vacuum. The product was purified by chromatography with dichloromethane:heptane=1:3 to yield 11.93 g (79% yield) 2,5-dibromo-3-(4-chloro-phenyl)-pyrazine as white crystals melting at 123-125° C. and as a byproduct 0.300 g 5-bromo-3-(4-chloro-phenyl)-2-(3-methyl-butoxy)-pyrazine as a yellow oil. MS (ISP) (M+H+)=357.0 and 355.0.

1. stirringThe mixture was stirred at room temperature for 2 h
2. customThe phases were separated
3. washthe organic phase washed with brine
4. additionTo the organic phase was added silica gel (ca. 100 g)
5. customthe solvent was removed under aspirator vacuum
6. customThe product was purified by chromatography with dichloromethane

ORD record

ord-f355292cfb5941998fa716da55f98453

Source dataset

uspto-grants-2009_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07629346B2