Hydrogen Bromide → 1-Bromo-2-tert-butylbenzene

To a solution of 2-tert-butylaniline (7.46 g, 50 mmol 15.6 mL) in hydrobromic acid (40% w/w, 15 mL) cooled at <5° C. (ice/salt bath), a solution of 7.55 g (0.11 mol) of sodium nitrite in 10 mL of water was added at a rate that the temperature did not exceed 10° C. (ca two hour addition time). When the diazotization was completed, 0.20 g of copper powder was added. (CAUTION: the solution was refluxed very cautiously because of vigorous gas evolution!). When the vigorous evolution of nitrogen subsided, the system was kept at 50° C. for 30 minutes and was then diluted with 80 mL of water and extracted three times with diethyl ether (100 mL each). The organic layer was washed with 10% solution of KOH; dried over Na2SO4, concentrated in vacuo, and purified by chromatography on silica gel chromatography. The product obtained was further distilled at 85° C. (3 mm Hg) to yield 1-bromo-2-tert-butylbenzene (2.88 g, 27%). 1H NMR (400 MHz, CDCl3): δ 7.58 (m, 1 H, Ph-H), 7.45 (m, 1 H, Ph-H), 7.24 (m, 1 H, Ph-H), 7.02 (m, 1 H, Ph-H), 1.51 (s, 9 H, C(CH3)3).

1. customdid not exceed 10° C.
2. addition(ca two hour addition time)
3. temperature(CAUTION: the solution was refluxed very cautiously because of vigorous gas evolution
4. extractionextracted three times with diethyl ether (100 mL each)
5. washThe organic layer was washed with 10% solution of KOH
6. dry with materialdried over Na2SO4
7. concentrationconcentrated in vacuo
8. custompurified by chromatography on silica gel chromatography
9. customThe product obtained
10. distillationwas further distilled at 85° C. (3 mm Hg)

ORD-Eintrag

ord-c9b1667ee01443eb8f05f3a6ec52e774

Quelldatensatz

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08497360B2