3,5-Dibromo-4-methylpyridin-2-amine → 3-Bromo-4-methylpyridin-2-amine

Temperature

-78 °C

To a solution of 3,5-dibromo-4-methyl-pyridin-2-ylamine (3.38 g, 12.7 mmol) in THF (60 mL) cooled to −78° C. was added n-BuLi (1.9M in pentane) (13.4 mL, 25.4 mmol) to give an orange solution. The solution was stirred at −78° C. for 1 h and then quenched with water (10 mL). The pH of the mixture was adjusted to ˜12 with 10N NaOH and then extracted with CH2Cl2 (3×30 mL), dried (Na2SO4), filtered and concentrated in vacuo to give an orange oil. Purification by column chromatography on silica gel (Et2O) afforded 3-bromo-4-methyl-pyridin-2-ylamine (1.68 g, 71%) as a pale yellow solid. 1H NMR (CDCl3) δ 2.32 (s, 3H), 5.00 (br s, 2H), 6.52 (d, 1H, J=6.0 Hz), 7.84 (d, 1H, J=6.0 Hz).

1. customto give an orange solution
2. customquenched with water (10 mL)
3. extractionextracted with CH2Cl2 (3×30 mL)
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto give an orange oil
8. customPurification by column chromatography on silica gel (Et2O)

ORD record

ord-66b8ab9f484d48448421cd75e67fabc9

Source dataset

uspto-grants-2009_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07498346B2