Allyl bromide → Pyrazine, 3-butenyl-

Temperature

-20 °C

A solution of lithium diisopropylamine [prepared from a solution of butyl lithium in hexanes (100 mL, 2.5M) and diisopropylamine (25.3 g) at −35° C.] was treated with a solution of 2-methylpyrazine (23.5 g) in dry tetrahydrofuran (300 mL) at −20° C. The mixture was stirred at −20° C. for 1 hour then cooled to −78° C. and treated with a solution of allyl bromide (30.8 g) in dry tetrahydrofuran (300 mL). This mixture was warmed to room temperature and stirred at this temperature for 2 hours then left overnight and then treated with saturated ammonium chloride solution (50 mL) followed by water (200 mL). The mixture was then extracted twice with ether (200 mL). The combined extracts were dried over magnesium sulfate then evaporated. The residue was distilled to give the title compound (22 g) as a colourless oil, b.p. 70° C./1 mm Hg.

1. temperaturethen cooled to −78° C.
2. temperatureThis mixture was warmed to room temperature
3. stirringstirred at this temperature for 2 hours
4. waitthen left overnight
5. extractionThe mixture was then extracted twice with ether (200 mL)
6. dry with materialThe combined extracts were dried over magnesium sulfate
7. customthen evaporated
8. distillationThe residue was distilled

ORD record

ord-4815e54b89fa4163900dcedc3ced0e59

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07943616B2