6-BroMo-7-chlorothieno[3,2-b]pyridine synthesis

Yield:875340-63-9 70%

Reaction Conditions:

with oxalyl dichloride;N,N-dimethyl-formamide in 1,2-dichloro-ethane at 0; for 3.16667 h;Heating / reflux;

Steps:

62; 223.2

DMF (0.72mL) was added slowly to a solution of (COC1)₂ in DCE at 0°C andthe mixture was stirred for 30 min, followed by addition of 270 (crude from above). Thecombined mixture was stirred for 10 min at the same conditions and was heated to reflux for3h. After cooling the mixture was concentrated and partitioned between DCM and water.Organic phase was collected and dried over anhydrous NaaSC^, filtered and concentrated.The residue was purified by flash column chromatography (eluent EtOAc), to afford thetitle compound 271 (0.66g, 70% yield based on compound 1) as a yellowish solid. MS(m/z): 249.0(M+H) (found).

References:

WO2006/10264,2006,A1 Location in patent:Page/Page column 205