Bromine → 4-Bromo-6-chloro-5-methylpyridazin-3-amine

The mixture of 6-chloro-5-methylpyridazin-3-amine and 3-chloro-5-methylpyridazin-6-amine (1.45 g, 10 mmol) from 1a and NaHCO3 (2.1 g, 25 mmol) were suspended in MeOH (20 mL) and treated with Br2 (0.57 mL, 11 mmol). The mixture was stirred at room temperature for 4 h, then filtered. The filtrate was condensed in vacuo. The resulting residue was resuspended in EtOAc (100 mL) and washed sequentially with sat. aqueous NaHCO3 solution (2×20 mL) and aqueous NaCl solution (1×20 mL). The solution was dried over MgSO4. The solvent was removed in vacuo to give crude 4-bromo-6-chloro-5-methylpyridazin-3-amine (1 g).

1. filtrationfiltered
2. customcondensed in vacuo
3. washwashed sequentially with sat. aqueous NaHCO3 solution (2×20 mL) and aqueous NaCl solution (1×20 mL)
4. dry with materialThe solution was dried over MgSO4
5. customThe solvent was removed in vacuo

ORD record

ord-e3c58a78953b4cfb8d08e35ebd2f641b

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07723336B2