Acetic Acid → 3-Bromo-N,N-dimethylaniline

Temperature

40 °C

According to the procedure of Borch and Hassid, J. Org. Chem. 37:1673 (1972), sodium cyanoborohydride (4.75 g, 75.0 mmol) was added to a stirred solution of 3-bromoaniline (4.30 g, 25.0 mmol) and 37% aqueous formaldehyde (20 mL, 0.25 moles) in acetonitrile (200 mL). Glacial acetic acid (2.5 mL) was added drop-wise (10 min) to the stirred suspension, without cooling. The temperature gradually increased to 40° C. After stirring for 2 h, the mixture was treated with a second 2.5 mL portion of acetic acid. Stirring was continued for another hour. The mixture was then poured into ether (400 mL) and extracted with 1 M aqueous KOH (3×100 mL). The ether layer was washed once with saturated aqueous NaCl, dried (K2CO3) and evaporated. This left a biphasic mixture, which was separated by careful pipetting. The larger fraction was vacuum distilled to give 4.13 g (82.6% yield) of colorless oil, bp 79-80° C. at 0.4 mm Hg.

1. temperaturewithout cooling
2. stirringStirring
3. waitwas continued for another hour
4. extractionextracted with 1 M aqueous KOH (3×100 mL)
5. washThe ether layer was washed once with saturated aqueous NaCl
6. dry with materialdried (K2CO3)
7. customevaporated
8. waitThis left a biphasic mixture, which
9. customwas separated by careful pipetting
10. distillationdistilled

ORD record

ord-90499fbeb62541ab9e8bc5bf8f47856f

Source dataset

uspto-grants-2002_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06337351B1