2-Bromo-8-chloroquinoline synthesis

Yield:891842-52-7 85%

Reaction Conditions:

with tetrabutylammomium bromide;phosphorus pentoxide in xylene at 220; for 0.277778 h;microwave irradiation;

Steps:

91.1

A mixture of 8-chloro-2-hydroxyquinolinone (200 mg, 1.11 mmol), P₂O₅ (383 mg, 2.67 mmol) and tetrabutylammonium bromide (429 mg, 1.33 mmol) in 4 mL xylene, was irradiated in a microwave reactor at 220° C. for 1000 s. The mixture was decanted and the rinsed with EtOAc (2×). The combined organic phase was washed with sat. NaHCO₃ and brine, dried (Na₂SO₄), filtered through a 1 pad of silica gel and concentrated to afford 229 mg (85%) of Intermediate 91.1 as an off-white solid, which was used without further purification.

References:

US2006/211720,2006,A1 Location in patent:Page/Page column 55